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Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Marie-Francoise Daza,

Laurent Ariza:

El amor

en los tiempos del coronavirus

LUCIO BOCCARDO

(Sapienza Universita di Roma - Istituto Lombardo)

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Singular Problems Associated to Quasilinear Equations

Singular ProblemsAssociated to QuasilinearEquationsA WORKSHOP IN CELEBRATION OF MARIE-FRANÇOISE BIDAUT-VÉRONAND LAURENT VÉRON’S 70TH BIRTHDAY.

June 1-3, 2020

The workshop will take place

over Zoom.

Organizers:

Quoc-Hung Nguyen, ShanghaiTech University

Phuoc-Tai Nguyen, Masaryk University

Speakers

The workshop is co-hosted by Institute of

Mathematical Sciences, ShanghaiTech University

and Department of Mathematics and Statistics,

Masaryk University.

Lucio Boccardo, UNIROMA1, Italy.

Huyuan Chen, JXNU, China.

Julián López Gómez, UCM, Spain.

Manuel Del Pino, Univ. of Bath, UK

Jesús Ildefonso Díaz, UCM, Spain.

Marta García-Huidobro, UC, Chile.

Moshe Marcus, Technion, Israel.

Giuseppe Mingione, UNIPR, Italy.

Vitaly Moroz, Swansea University, UK.

Nguyen Cong Phuc, LSU, USA.

Van Tien Nguyen, NYU, Abu Dhabi.

Alessio Porretta, UNIROMA2, Italy.

Patrizia Pucci, UNIPG, Italy.

Philippe Souplet, LAGA, France

Igor Verbitsky, Univ. of Missouri, USA.

Juan Luis Vázquez, UAM, Spain.

Feng Zhou, ECNU, China.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Singular Problems Associated to Quasilinear Equations

A WORKSHOP IN CELEBRATION OF MARIE-FRANCOISEBIDAUT-VERON AND LAURENT VERON’S 70TH BIRTHDAY.

Bonjour

Buon giorno

Good morning

+thanks to the organizers

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Singular Problems Associated to Quasilinear Equations

A WORKSHOP IN CELEBRATION OF MARIE-FRANCOISEBIDAUT-VERON AND LAURENT VERON’S 70TH BIRTHDAY.

Bonjour

Buon giorno

Good morning

+thanks to the organizers

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Singular Problems Associated to Quasilinear Equations

A WORKSHOP IN CELEBRATION OF MARIE-FRANCOISEBIDAUT-VERON AND LAURENT VERON’S 70TH BIRTHDAY.

Bonjour

Buon giorno

Good morning

+thanks to the organizers

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

El amor en los tiempos del coronavirus

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

El amor en los tiempos del coronavirus

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

El amor en los tiempos del coronavirus

G.G.M.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

L’amour aux temps du corona

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

L’amour aux temps du corona

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

A WORKSHOP IN CELEBRATION OF MARIE-FRANCOISEBIDAUT-VERON AND LAURENT VERON’S 70TH BIRTHDAY.

1 . 6 . 2020

Bon anniversaire

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

A WORKSHOP IN CELEBRATION OF MARIE-FRANCOISEBIDAUT-VERON AND LAURENT VERON’S 70TH BIRTHDAY.

1 . 6 . 2020

Bon anniversaire

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

A WORKSHOP IN CELEBRATION OF MARIE-FRANCOISEBIDAUT-VERON AND LAURENT VERON’S 70TH BIRTHDAY.

1 . 6 . 2020

Bon anniversaire

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

A WORKSHOP IN CELEBRATION OF MARIE-FRANCOISEBIDAUT-VERON AND LAURENT VERON’S 70TH BIRTHDAY.

1 . 6 . 2020

Bon anniversaire

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

Maximum principle

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

Maximum principle

Two maximum principles for two friends

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

Maximum principle

Two maximum principles for two friends

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

Maximum principle

Two maximum principles for two friends

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

Maximum principle

Two maximum principles for two friends

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Les mathematiques aux temps du corona

Maximum principle

Two maximum principles for two friends

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0sketch:

Tk(s)

−k

−k

k

k

−kk

Gk(s)

−k

k

Th(Gk(s))/h

−k − h

-1

k + h

1

1

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0sketch:

Tk(s)

−k

−k

k

k

−kk

Gk(s)

−k

k

Th(Gk(s))/h

−k − h

-1

k + h

1

1

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0sketch:

Tk(s)

−k

−k

k

k

−kk

Gk(s)

−k

k

Th(Gk(s))/h

−k − h

-1

k + h

1

1

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

sketch:

Tk(s)

−k

−k

k

k

−kk

Gk(s)

−k

k

Th(Gk(s))/h

−k − h

-1

k + h

1

1

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0sketch:

Tk(s)

−k

−k

k

k

−kk

Gk(s)

−k

k

Th(Gk(s))/h

−k − h

-1

k + h

1

1

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0sketch:

Tk(s)

−k

−k

k

k

−kk

Gk(s)

−k

k

Th(Gk(s))/h

−k − h

-1

k + h

1

1

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

sketch :

α

∫Ω

|∇Gk(un)|2 +

∫Ω

an(x)|un|γ|Gk(un)|

≤∫

Ω

|fn||Gk(un)| ≤∫

Ω

Q an(x)|Gk(un)|

⇒posit. +

∫Ω

an(x)[|un|γ − Q]|Gk(un)| ≤ 0

⇒|un| ≤ Q1γ ...⇒... ∃ |u| ≤ Q

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

sketch : α

∫Ω

|∇Gk(un)|2 +

∫Ω

an(x)|un|γ|Gk(un)|

≤∫

Ω

|fn||Gk(un)| ≤∫

Ω

Q an(x)|Gk(un)|

⇒posit. +

∫Ω

an(x)[|un|γ − Q]|Gk(un)| ≤ 0

⇒|un| ≤ Q1γ ...⇒... ∃ |u| ≤ Q

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

sketch : α

∫Ω

|∇Gk(un)|2 +

∫Ω

an(x)|un|γ|Gk(un)|

≤∫

Ω

|fn||Gk(un)| ≤∫

Ω

Q an(x)|Gk(un)|

posit. +

∫Ω

an(x)[|un|γ − Q]|Gk(un)| ≤ 0

⇒|un| ≤ Q1γ ...⇒... ∃ |u| ≤ Q

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

u ∈ W 1,20 (Ω) ∩ L∞(Ω)

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

sketch : α

∫Ω

|∇Gk(un)|2 +

∫Ω

an(x)|un|γ|Gk(un)|

≤∫

Ω

|fn||Gk(un)| ≤∫

Ω

Q an(x)|Gk(un)|

⇒posit. +

∫Ω

an(x)[|un|γ − Q]|Gk(un)| ≤ 0

⇒|un| ≤ Q1γ ...⇒... ∃ |u| ≤ Q

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

∃ : u ∈ W 1,20 (Ω) ∩ L∞(Ω), |u| ≤ Q

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

f=Q a: −div(M(x)∇u)+a(x)uγ =Q a(x), γ > 0

−div(M(x)∇u)=a(x)[Q − uγ] ≥ T1a(x)[Q − uγ] ≥ 0⇒⇒u satisfies Strong Maximum Principle,even if 0 < γ < 1.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

∃ : u ∈ W 1,20 (Ω) ∩ L∞(Ω), |u| ≤ Q

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

f=Q a:

−div(M(x)∇u)+a(x)uγ =Q a(x), γ > 0

−div(M(x)∇u)=a(x)[Q − uγ] ≥ T1a(x)[Q − uγ] ≥ 0⇒⇒u satisfies Strong Maximum Principle,even if 0 < γ < 1.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

∃ : u ∈ W 1,20 (Ω) ∩ L∞(Ω), |u| ≤ Q

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

f=Q a: −div(M(x)∇u)+a(x)uγ =Q a(x), γ > 0

−div(M(x)∇u)=a(x)[Q − uγ] ≥ T1a(x)[Q − uγ] ≥ 0⇒⇒u satisfies Strong Maximum Principle,even if 0 < γ < 1.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

∃ : u ∈ W 1,20 (Ω) ∩ L∞(Ω), |u| ≤ Q

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

f=Q a: −div(M(x)∇u)+a(x)uγ =Q a(x), γ > 0

−div(M(x)∇u)=a(x)[Q − uγ] ≥ T1a(x)[Q − uγ] ≥ 0

⇒⇒u satisfies Strong Maximum Principle,even if 0 < γ < 1.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

∃ : u ∈ W 1,20 (Ω) ∩ L∞(Ω), |u| ≤ Q

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

f=Q a: −div(M(x)∇u)+a(x)uγ =Q a(x), γ > 0

−div(M(x)∇u)=a(x)[Q − uγ] ≥ T1a(x)[Q − uγ] ≥ 0⇒⇒

u satisfies Strong Maximum Principle,even if 0 < γ < 1.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

∃ : u ∈ W 1,20 (Ω) ∩ L∞(Ω), |u| ≤ Q

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

f=Q a: −div(M(x)∇u)+a(x)uγ =Q a(x), γ > 0

−div(M(x)∇u)=a(x)[Q − uγ] ≥ T1a(x)[Q − uγ] ≥ 0⇒⇒u satisfies Strong Maximum Principle,

even if 0 < γ < 1.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Maximum principle

A remark dedicated to Marie-Francoise, by David A. and Lucio B. / following [AB,JFA 2014]

Ω bounded open subset of RN

M(x) bounded elliptic matrix

|f (x)| ≤ Q a(x) ∈ L1(Ω), Q > 0

∃ : u ∈ W 1,20 (Ω) ∩ L∞(Ω), |u| ≤ Q

−div(M(x)∇u)+a(x)u|u|γ−1 = f , γ > 0

f=Q a: −div(M(x)∇u)+a(x)uγ =Q a(x), γ > 0

−div(M(x)∇u)=a(x)[Q − uγ] ≥ T1a(x)[Q − uγ] ≥ 0⇒⇒u satisfies Strong Maximum Principle,even if 0 < γ < 1.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Lower order term: Convection/Drift terms

We discuss the existence properties and of distributionalsolutions for the boundary value problems (the firstwith a convection term, the second with a drift term)

−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,

We note that

at least formally, if M(x) is symmetric, the twoabove linear problems are in duality.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Lower order term: Convection/Drift terms

We discuss the existence properties and of distributionalsolutions for the boundary value problems (the firstwith a convection term, the second with a drift term)

−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,

We note that

at least formally, if M(x) is symmetric, the twoabove linear problems are in duality.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Lower order term: Convection/Drift terms

We discuss the existence properties and of distributionalsolutions for the boundary value problems (the firstwith a convection term, the second with a drift term)

−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,

We note that

at least formally, if M(x) is symmetric, the twoabove linear problems are in duality.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Lower order term: Convection/Drift terms

We discuss the existence properties and of distributionalsolutions for the boundary value problems (the firstwith a convection term, the second with a drift term)

−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,

We note that

at least formally, if M(x) is symmetric, the twoabove linear problems are in duality.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,

We note that

the differential operators may be not coercive,unless one assumes that either the norm of |E | inLN(Ω) is small, or that div(‖E‖

N) = 0: ...

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,

We note that

the differential operators may be not coercive,unless one assumes that either the norm of |E | inLN(Ω) is small, or that div(‖E‖

N) = 0: ...

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,

We note that

the differential operators may be not coercive,unless one assumes that either the norm of |E | inLN(Ω) is small, or that div(‖E‖

N) = 0: ...

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Papers concerned with this part of the talk

L. Boccardo: Some developments on Dirichlet problemswith discontinuous coefficients; Boll. Unione Mat. Ital, 2(2009) 285–297.(invited paper in memory of 30-death Stampacchia)

L. Boccardo: Dirichlet problems with singularconvection terms and applications; J. DifferentialEquations, 258 (2015) 2290–2314.

L. Boccardo: Stampacchia-Calderon-Zygmund theoryfor linear elliptic equations with discontinuouscoefficients and singular drift; ESAIM, Control,Optimization and Calculus of Variations, 25 (2019), Art.47, 13 pp.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Assumptions

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω.

Ω bounded subset of RN ,

ellipticity: 0 < α, α|ξ|2 ≤ M(x)ξξ, |M(x)|1 ≤ β,

f ∈ Lm(Ω), 1 ≤ m ≤ ∞,

E ∈ (LN(Ω))N

1 1: dependence w.r.t. x / 2: nonsmooth dependence /Mingione

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Assumptions

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω.

Ω bounded subset of RN ,

ellipticity:

0 < α, α|ξ|2 ≤ M(x)ξξ, |M(x)|1 ≤ β,

f ∈ Lm(Ω), 1 ≤ m ≤ ∞,

E ∈ (LN(Ω))N

1 1: dependence w.r.t. x / 2: nonsmooth dependence /Mingione

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Assumptions

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω.

Ω bounded subset of RN ,

ellipticity: 0 < α, α|ξ|2 ≤ M(x)ξξ, |M(x)|1 ≤ β,

f ∈ Lm(Ω), 1 ≤ m ≤ ∞,

E ∈ (LN(Ω))N

1 1: dependence w.r.t. x / 2: nonsmooth dependence /Mingione

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Assumptions

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω.

Ω bounded subset of RN ,

ellipticity: 0 < α, α|ξ|2 ≤ M(x)ξξ, |M(x)|1 ≤ β,

f ∈ Lm(Ω), 1 ≤ m ≤ ∞,

E ∈ (LN(Ω))N

1 1: dependence w.r.t. x / 2: nonsmooth dependence /Mingione

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Boundary value problem and Lax-Milgram

u weak /distributional solution of the boundary valueproblem

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,u = 0 : ∂Ω.

means

u ∈ W 1,20 (Ω) :

∫Ω

M(x)∇u∇v =

∫Ω

u E (x)∇v +

∫Ω

f (x)v ,

∀ v ∈ W 1,20 (Ω)/smooth

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Boundary value problem and Lax-Milgram

u weak

/distributional solution of the boundary valueproblem

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,u = 0 : ∂Ω.

means

u ∈ W 1,20 (Ω) :

∫Ω

M(x)∇u∇v =

∫Ω

u E (x)∇v +

∫Ω

f (x)v ,

∀ v ∈ W 1,20 (Ω)/smooth

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Boundary value problem and Lax-Milgram

u weak /distributional

solution of the boundary valueproblem

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,u = 0 : ∂Ω.

means

u ∈ W 1,20 (Ω) :

∫Ω

M(x)∇u∇v =

∫Ω

u E (x)∇v +

∫Ω

f (x)v ,

∀ v ∈ W 1,20 (Ω)/smooth

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Boundary value problem and Lax-Milgram

u weak /distributional solution of the boundary valueproblem

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,u = 0 : ∂Ω.

means

u ∈ W 1,20 (Ω) :

∫Ω

M(x)∇u∇v =

∫Ω

u E (x)∇v +

∫Ω

f (x)v ,

∀ v ∈ W 1,20 (Ω)

/smooth

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Boundary value problem and Lax-Milgram

u weak /distributional solution of the boundary valueproblem

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,u = 0 : ∂Ω.

means

u ∈ W 1,20 (Ω) :

∫Ω

M(x)∇u∇v =

∫Ω

u E (x)∇v +

∫Ω

f (x)v ,

∀ v ∈ W 1,20 (Ω)/smooth

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Coercivity of −div(M(x)∇u) + div(u E(x))

∫Ω

M(x)∇v∇v ±∫

Ω

v E (x)∇v

≥ α

∫Ω

|∇v |2 −[ ∫

Ω

|v |2∗] 1

2∗[ ∫

Ω

|E (x)|N] 1

N[ ∫

Ω

|∇v |2] 1

2

≥α− 1

S

[ ∫Ω

|E (x)|N] 1

N∫

Ω

|∇v |2

E ∈ LN

‖E‖LN

not too large

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Coercivity of −div(M(x)∇u) + div(u E(x))

∫Ω

M(x)∇v∇v ±∫

Ω

v E (x)∇v

≥ α

∫Ω

|∇v |2 −[ ∫

Ω

|v |2∗] 1

2∗[ ∫

Ω

|E (x)|N] 1

N[ ∫

Ω

|∇v |2] 1

2

≥α− 1

S

[ ∫Ω

|E (x)|N] 1

N∫

Ω

|∇v |2

E ∈ LN

‖E‖LN

not too large

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Coercivity of −div(M(x)∇u) + div(u E(x))

∫Ω

M(x)∇v∇v ±∫

Ω

v E (x)∇v

≥ α

∫Ω

|∇v |2 −[ ∫

Ω

|v |2∗] 1

2∗[ ∫

Ω

|E (x)|N] 1

N[ ∫

Ω

|∇v |2] 1

2

≥α− 1

S

[ ∫Ω

|E (x)|N] 1

N∫

Ω

|∇v |2

E ∈ LN

‖E‖LN

not too large

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Coercivity of −div(M(x)∇u) + div(u E(x))

∫Ω

M(x)∇v∇v ±∫

Ω

v E (x)∇v

≥ α

∫Ω

|∇v |2 −[ ∫

Ω

|v |2∗] 1

2∗[ ∫

Ω

|E (x)|N] 1

N[ ∫

Ω

|∇v |2] 1

2

≥α− 1

S

[ ∫Ω

|E (x)|N] 1

N∫

Ω

|∇v |2

E ∈ LN

‖E‖LN

not too large

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Coercivity of −div(M(x)∇u) + div(u E(x))

∫Ω

M(x)∇v∇v ±∫

Ω

v E (x)∇v

≥ α

∫Ω

|∇v |2 −[ ∫

Ω

|v |2∗] 1

2∗[ ∫

Ω

|E (x)|N] 1

N[ ∫

Ω

|∇v |2] 1

2

≥α− 1

S

[ ∫Ω

|E (x)|N] 1

N∫

Ω

|∇v |2

E ∈ LN

‖E‖LN

not too large

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Coercivity of −div(M(x)∇u) + div(u E(x))

∫Ω

M(x)∇v∇v ±∫

Ω

v E (x)∇v

≥ α

∫Ω

|∇v |2 −[ ∫

Ω

|v |2∗] 1

2∗[ ∫

Ω

|E (x)|N] 1

N[ ∫

Ω

|∇v |2] 1

2

≥α− 1

S

[ ∫Ω

|E (x)|N] 1

N∫

Ω

|∇v |2

E ∈ LN

‖E‖LN

not too large

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Our approach hinges on test function method

The proofs of all the results are very easy

if we assume div(E ) = 0

if we assume ‖E‖N

small

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Coercivity

Our approach hinges on test function method

The proofs of all the results are very easy

if we assume div(E ) = 0

if we assume ‖E‖N

small

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

Stampacchia-Calderon-Zygmund for the two problems

−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,2

−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,3

Ω bounded subset of RN ,ellipticity: 0 < α, α|ξ|2 ≤ M(x)ξξ, |M(x)| ≤ β,f ∈ Lm(Ω), 1 ≤ m ≤ ∞,

E ∈ (LN(Ω))N

and we prove for both the b.v.p. the sameStampacchia-Calderon-Zygmund results of the caseE = 0 .

2 paper invitation U.M.I. in memory of 30-Stampacchia3 ESAIM-COCV 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

Stampacchia-Calderon-Zygmund for the two problems−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,2

−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,3

Ω bounded subset of RN ,ellipticity: 0 < α, α|ξ|2 ≤ M(x)ξξ, |M(x)| ≤ β,f ∈ Lm(Ω), 1 ≤ m ≤ ∞,

E ∈ (LN(Ω))N

and we prove for both the b.v.p. the sameStampacchia-Calderon-Zygmund results of the caseE = 0 .

2 paper invitation U.M.I. in memory of 30-Stampacchia3 ESAIM-COCV 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

Stampacchia-Calderon-Zygmund for the two problems−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,2

−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,3

Ω bounded subset of RN ,ellipticity: 0 < α, α|ξ|2 ≤ M(x)ξξ, |M(x)| ≤ β,f ∈ Lm(Ω), 1 ≤ m ≤ ∞,

E ∈ (LN(Ω))N

and we prove for both the b.v.p. the sameStampacchia-Calderon-Zygmund results of the caseE = 0 .

2 paper invitation U.M.I. in memory of 30-Stampacchia3 ESAIM-COCV 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

Stampacchia-Calderon-Zygmund for the two problems−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,2

−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,3

Ω bounded subset of RN ,ellipticity: 0 < α, α|ξ|2 ≤ M(x)ξξ, |M(x)| ≤ β,f ∈ Lm(Ω), 1 ≤ m ≤ ∞,

E ∈ (LN(Ω))N

and we prove for both the b.v.p. the sameStampacchia-Calderon-Zygmund results of the case

E = 0 .

2 paper invitation U.M.I. in memory of 30-Stampacchia3 ESAIM-COCV 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

Stampacchia-Calderon-Zygmund for the two problems−div(M(x)∇u) = −div(u E (x)) + f (x) in Ω,

u = 0 on ∂Ω,2

−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,3

Ω bounded subset of RN ,ellipticity: 0 < α, α|ξ|2 ≤ M(x)ξξ, |M(x)| ≤ β,f ∈ Lm(Ω), 1 ≤ m ≤ ∞,

E ∈ (LN(Ω))N

and we prove for both the b.v.p. the sameStampacchia-Calderon-Zygmund results of the caseE = 0 .

2 paper invitation U.M.I. in memory of 30-Stampacchia3 ESAIM-COCV 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

|E | ∈ LN(Ω)

as E = 0

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

|E | ∈ LN(Ω)

as E = 0

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

|E | ∈ LN(Ω)

as E = 0

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

1 2NN+2≤ m < N

2⇒ u ∈ W 1,2

0 (Ω) ∩ Lm∗∗(Ω);2 1 < m < 2N

N+2⇒ u ∈ W 1,m∗

0 (Ω);3 m = 1 ⇒ u ∈ W 1,q

0 (Ω), q < NN−1

.

u :

∫Ω

M∇u∇φ =

∫Ω

u E∇φ +

∫Ω

f φ, ∀φ ∈ D.

Theorem (70-Brezis)

E = 0, m > N2

, it is false that u ∈ W 1,m∗

0 (Ω)

Remark

E = 0, 2NN+2

+ δMeyers < m < N2

, u ∈?

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

|E | ∈ LN(Ω)

as E = 0−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

1 2NN+2≤ m < N

2⇒ u ∈ W 1,2

0 (Ω) ∩ Lm∗∗(Ω);

2 1 < m < 2NN+2⇒ u ∈ W 1,m∗

0 (Ω);3 m = 1 ⇒ u ∈ W 1,q

0 (Ω), q < NN−1

.

u :

∫Ω

M∇u∇φ =

∫Ω

u E∇φ +

∫Ω

f φ, ∀φ ∈ D.

Theorem (70-Brezis)

E = 0, m > N2

, it is false that u ∈ W 1,m∗

0 (Ω)

Remark

E = 0, 2NN+2

+ δMeyers < m < N2

, u ∈?

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

|E | ∈ LN(Ω)

as E = 0−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

1 2NN+2≤ m < N

2⇒ u ∈ W 1,2

0 (Ω) ∩ Lm∗∗(Ω);2 1 < m < 2N

N+2⇒ u ∈ W 1,m∗

0 (Ω);3 m = 1

⇒ u ∈ W 1,q0 (Ω), q < N

N−1.

u :

∫Ω

M∇u∇φ =

∫Ω

u E∇φ +

∫Ω

f φ, ∀φ ∈ D.

Theorem (70-Brezis)

E = 0, m > N2

, it is false that u ∈ W 1,m∗

0 (Ω)

Remark

E = 0, 2NN+2

+ δMeyers < m < N2

, u ∈?

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

|E | ∈ LN(Ω)

as E = 0−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

1 2NN+2≤ m < N

2⇒ u ∈ W 1,2

0 (Ω) ∩ Lm∗∗(Ω);2 1 < m < 2N

N+2⇒ u ∈ W 1,m∗

0 (Ω);3 m = 1 ⇒ u ∈ W 1,q

0 (Ω), q < NN−1

.

u :

∫Ω

M∇u∇φ =

∫Ω

u E∇φ +

∫Ω

f φ, ∀φ ∈ D.

Theorem (70-Brezis)

E = 0, m > N2

, it is false that u ∈ W 1,m∗

0 (Ω)

Remark

E = 0, 2NN+2

+ δMeyers < m < N2

, u ∈?

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

|E | ∈ LN(Ω)

as E = 0−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

1 2NN+2≤ m < N

2⇒ u ∈ W 1,2

0 (Ω) ∩ Lm∗∗(Ω);2 1 < m < 2N

N+2⇒ u ∈ W 1,m∗

0 (Ω);3 m = 1 ⇒ u ∈ W 1,q

0 (Ω), q < NN−1

.

u :

∫Ω

M∇u∇φ =

∫Ω

u E∇φ +

∫Ω

f φ, ∀φ ∈ D.

Theorem (70-Brezis)

E = 0, m > N2

, it is false that u ∈ W 1,m∗

0 (Ω)

Remark

E = 0, 2NN+2

+ δMeyers < m < N2

, u ∈?

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

|E | ∈ LN(Ω)

as E = 0−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

1 2NN+2≤ m < N

2⇒ u ∈ W 1,2

0 (Ω) ∩ Lm∗∗(Ω);2 1 < m < 2N

N+2⇒ u ∈ W 1,m∗

0 (Ω);3 m = 1 ⇒ u ∈ W 1,q

0 (Ω), q < NN−1

.

u :

∫Ω

M∇u∇φ =

∫Ω

u E∇φ +

∫Ω

f φ, ∀φ ∈ D.

Theorem (70-Brezis)

E = 0, m > N2

, it is false that u ∈ W 1,m∗

0 (Ω)

Remark

E = 0, 2NN+2

+ δMeyers < m < N2

, u ∈?

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

Same results for the drift problem

−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,4

4 ESAIM-COCV 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

Same results for the drift problem

−div(M(x)∇ψ) = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,4

4 ESAIM-COCV 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

“Nonlinear”

approach to a linear problem

−div(M(x)∇un) = −div( un

1 + 1n|un|

E (x))

+ f (x)

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

“Nonlinear”

approach to a linear problem

−div(M(x)∇un) = −div( un

1 + 1n|un|

E (x))

+ f (x)

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

“Nonlinear” approach to a linear problem

−div(M(x)∇un) = −div( un

1 + 1n|un|

E (x))

+ f (x)

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Existence of weak/distributional solutions. Summability properties of solutions

Other recent papers

L. Boccardo, S. Buccheri, G.R. Cirmi: Two linear noncoerciveDirichlet problems in duality; Milan J. Math. 86 (2018),97–104.

L. Boccardo, S. Buccheri, R.G. Cirmi: Calderon-Zygmundtheory for infinite energy solutions of nonlinear ellipticequations with singular drift; NODEA, to appear.

L. Boccardo, S. Buccheri: A nonlinear homotopy between twolinear Dirichlet problems; Rev. Mat. Complutense, to appear.

L. Boccardo: Two semilinear Dirichlet problems “almost” induality; Boll. Unione Mat. Ital. 12 (2019), 349–356.

L. Boccardo, L. Orsina, A. Porretta: Some noncoerciveparabolic equations with lower order terms in divergence form.Dedicated to Philippe Benilan. J. Evol. Equ. 3 (2003),407–418.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((E ∈ (LN (Ω))N

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((E ∈ (LN (Ω))N

If E 6∈ (LN(Ω))N , even for nothing, as in

|E | ≤ |A||x | , A ∈ R , 0 ∈ Ω,

the framework changes completely:u ∈W 1,2

0 (Ω) or u ∈W 1,q0 (Ω) depends on the size of A . 5

1) if |A| < α(N−2m)m

, and 2NN+2≤ m < N

2, then

u ∈ W 1,20 (Ω) ∩ Lm∗∗(Ω);

2) if |A| < α(N−2m)m

, and 1 < m < 2NN+2

, then

u ∈ W 1,m∗

0 (Ω);

3) if |A| < α(N − 2), and m = 1, then ∇u ∈ (MN

N−1 (Ω))N

and u ∈ W 1,q0 (Ω), for every q < N

N−1;

4) if α(N − 2) ≤ |A| < α(N − 1), then u ∈ W 1,q0 (Ω), for

every q < Nα|A|+α

5JDE 2015; +Orsina, Nonlin.Anal. 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((E ∈ (LN (Ω))N

If E 6∈ (LN(Ω))N , even for nothing, as in

|E | ≤ |A||x | , A ∈ R , 0 ∈ Ω,

the framework changes completely:u ∈W 1,2

0 (Ω) or u ∈W 1,q0 (Ω) depends on the size of A . 5

1) if |A| < α(N−2m)m

, and 2NN+2≤ m < N

2, then

u ∈ W 1,20 (Ω) ∩ Lm∗∗(Ω);

2) if |A| < α(N−2m)m

, and 1 < m < 2NN+2

, then

u ∈ W 1,m∗

0 (Ω);

3) if |A| < α(N − 2), and m = 1, then ∇u ∈ (MN

N−1 (Ω))N

and u ∈ W 1,q0 (Ω), for every q < N

N−1;

4) if α(N − 2) ≤ |A| < α(N − 1), then u ∈ W 1,q0 (Ω), for

every q < Nα|A|+α

5JDE 2015; +Orsina, Nonlin.Anal. 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((E ∈ (LN (Ω))N

If E 6∈ (LN(Ω))N , even for nothing, as in

|E | ≤ |A||x | , A ∈ R , 0 ∈ Ω,

the framework changes completely:u ∈W 1,2

0 (Ω) or u ∈W 1,q0 (Ω) depends on the size of A . 5

1) if |A| < α(N−2m)m

, and 2NN+2≤ m < N

2, then

u ∈ W 1,20 (Ω) ∩ Lm∗∗(Ω);

2) if |A| < α(N−2m)m

, and 1 < m < 2NN+2

, then

u ∈ W 1,m∗

0 (Ω);

3) if |A| < α(N − 2), and m = 1, then ∇u ∈ (MN

N−1 (Ω))N

and u ∈ W 1,q0 (Ω), for every q < N

N−1;

4) if α(N − 2) ≤ |A| < α(N − 1), then u ∈ W 1,q0 (Ω), for

every q < Nα|A|+α

5JDE 2015; +Orsina, Nonlin.Anal. 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((E ∈ (LN (Ω))N

Radial ex.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((((((((((E ∈ (LN (Ω))N

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((((((((((E ∈ (LN (Ω))N

E ∈ (L2(Ω))N

definition of solution;

existence of solution.6

6 JDE 2015

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((((((((((E ∈ (LN (Ω))N

E ∈ (L2(Ω))N definition of solution;

existence of solution.6

6 JDE 2015

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((((((((((E ∈ (LN (Ω))N

If we add the zero order term “+u”, the framework changes completely.

A , un ∈ W 1,20 (Ω) :

−div(M(x)∇un) + A un = −div( un

1 + 1n|un|

E (x))

+ f (x)

Simpler proofs

PhD course, UCM, November 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((((((((((E ∈ (LN (Ω))N

If we add the zero order term “+u”, the framework changes completely.

A , un ∈ W 1,20 (Ω) :

−div(M(x)∇un) + A un = −div( un

1 + 1n|un|

E (x))

+ f (x)

Simpler proofs

PhD course, UCM, November 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((((((((((E ∈ (LN (Ω))N

If we add the zero order term “+u”, the framework changes completely.

A , un ∈ W 1,20 (Ω) :

−div(M(x)∇un) + A un = −div( un

1 + 1n|un|

E (x))

+ f (x)

Simpler proofs

PhD

course, UCM, November 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

(((((((((((((E ∈ (LN (Ω))N

If we add the zero order term “+u”, the framework changes completely.

A , un ∈ W 1,20 (Ω) :

−div(M(x)∇un) + A un = −div( un

1 + 1n|un|

E (x))

+ f (x)

Simpler proofs

PhD course, UCM, November 2019

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Impact of a zero order term

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Impact of a zero order term

By duality: problems with very singular drifts

−div(M(x)∇ψ) + ψ = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,7

E ∈ L2 8, f bounded ⇒ u ∈ W 1,20 (Ω), bounded;

application to the existence in some Hamilton-J.eq. with lower order term having q-dependencew.r.t. gradient, q < 2.

7 DIE 20198 only L2

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Impact of a zero order term

By duality: problems with very singular drifts

−div(M(x)∇ψ) + ψ = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,7

E ∈ L2 8, f bounded ⇒ u ∈ W 1,20 (Ω), bounded;

application to the existence in some Hamilton-J.eq. with lower order term having q-dependencew.r.t. gradient, q < 2.

7 DIE 20198 only L2

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Impact of a zero order term

By duality: problems with very singular drifts

−div(M(x)∇ψ) + ψ = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,7

E ∈ L2 8, f bounded ⇒ u ∈ W 1,20 (Ω), bounded;

application to the existence in some Hamilton-J.eq. with lower order term having q-dependencew.r.t. gradient, q < 2.

7 DIE 20198 only L2

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Impact of a zero order term

By duality: problems with very singular drifts

−div(M(x)∇ψ) + ψ = E (x)∇ψ + g(x) in Ω,

ψ = 0 on ∂Ω,7

E ∈ L2 8, f bounded ⇒ u ∈ W 1,20 (Ω), bounded;

application to the existence in some Hamilton-J.eq. with lower order term having q-dependencew.r.t. gradient, q < 2.

7 DIE 20198 only L2

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Impact of a zero order term

An elliptic system connected with the mathematical study of PDE models forchemotaxis

−div(A(x)∇u) + u = −div(u M(x)∇ψ) + f (x) ,−div(M(x)∇ψ) = uθ .

910

9JDE 201510Comm.PDE + L. Orsina

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Impact of a zero order term

An elliptic system connected with the mathematical study of PDE models forchemotaxis

−div(A(x)∇u) + u = −div(u M(x)∇ψ) + f (x) ,−div(M(x)∇ψ) = uθ .

910

9JDE 201510Comm.PDE + L. Orsina

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Convection [L.B. 2020]

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Convection [L.B. 2020]

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

E , f ∈ ?

Theorem

E ∈ (LN(Ω))N , f ∈ Lm(Ω) with m ≥ 2NN+2

and f (x) ≥ 0 (of

course not zero a.e.). Then the solution u ∈ W 1,20 (Ω) is

positive and it is zero at most on a set of zeroLebesgue measure a.

a weak max. pr.

Remark

In the proof we only need E ∈ (L2(Ω))N : blue and redassumptions.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Convection [L.B. 2020]

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

E , f ∈

?

Theorem

E ∈ (LN(Ω))N , f ∈ Lm(Ω) with m ≥ 2NN+2

and f (x) ≥ 0 (of

course not zero a.e.). Then the solution u ∈ W 1,20 (Ω) is

positive and it is zero at most on a set of zeroLebesgue measure a.

a weak max. pr.

Remark

In the proof we only need E ∈ (L2(Ω))N : blue and redassumptions.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Convection [L.B. 2020]

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

E , f ∈ ?

Theorem

E ∈ (LN(Ω))N , f ∈ Lm(Ω) with m ≥ 2NN+2

and f (x) ≥ 0 (of

course not zero a.e.). Then the solution u ∈ W 1,20 (Ω) is

positive and it is zero at most on a set of zeroLebesgue measure a.

a weak max. pr.

Remark

In the proof we only need E ∈ (L2(Ω))N : blue and redassumptions.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Convection [L.B. 2020]

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

E , f ∈ ?

Theorem

E ∈ (LN(Ω))N , f ∈ Lm(Ω) with m ≥ 2NN+2

and f (x) ≥ 0 (of

course not zero a.e.). Then the solution u ∈ W 1,20 (Ω) is

positive and it is zero at most on a set of zeroLebesgue measure a.

a weak max. pr.

Remark

In the proof we only need E ∈ (L2(Ω))N : blue and redassumptions.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Convection [L.B. 2020]

−div(M(x)∇u)) = −div(u E (x)) + f (x) : Ω,

u = 0 : ∂Ω

E , f ∈ ?

Theorem

E ∈ (LN(Ω))N , f ∈ Lm(Ω) with m ≥ 2NN+2

and f (x) ≥ 0 (of

course not zero a.e.). Then the solution u ∈ W 1,20 (Ω) is

positive and it is zero at most on a set of zeroLebesgue measure a.

a weak max. pr.

Remark

In the proof we only need E ∈ (L2(Ω))N : blue and redassumptions.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Drift [L.B. 2020]

−div(M(x)∇ψ)) = −div(ψ E (x)) + g(x) : Ω,

ψ = 0 : ∂Ω

Theorem

E ∈ (LN(Ω))N , g ∈ Lm(Ω) with m ≥ 2NN+2

and g(x) ≥ 0 (of

course not zero a.e.). Then the solution u ∈ W 1,20 (Ω) is

positive and it is zero at most on a set of zeroLebesgue measure a.

a weak max. pr.

Remark

In the proof we only need E ∈ (L2(Ω))N : blue and redassumptions.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

First Maximum Principle, dedicated to Marie-Francoise

Drift [L.B. 2020]

−div(M(x)∇ψ)) = −div(ψ E (x)) + g(x) : Ω,

ψ = 0 : ∂Ω

Theorem

E ∈ (LN(Ω))N , g ∈ Lm(Ω) with m ≥ 2NN+2

and g(x) ≥ 0 (of

course not zero a.e.). Then the solution u ∈ W 1,20 (Ω) is

positive and it is zero at most on a set of zeroLebesgue measure a.

a weak max. pr.

Remark

In the proof we only need E ∈ (L2(Ω))N : blue and redassumptions.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

with Alberto Farina

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

with Alberto Farina

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

books

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

books

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

in a conference in Cortona (organizers Juan Luis and Lucio)

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

in a conference in Cortona (organizers Juan Luis and Lucio)

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Calculus of Variations (in the study of integral functionals)

Recall this large and important class of integralfunctionals

J(v) =1

2

∫Ω

A(x , v)|∇v |2 +λ

2

∫Ω

v 2 −∫

Ω

f v λ > 0.

The Euler-Lagrange equation for J is (at least formally)the quasilinear elliptic problem−div(A(x , u)∇u) + 1

2A′(x , u)|∇u|2 + λ u = f in Ω,

u = 0 on ∂Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Calculus of Variations (in the study of integral functionals)

Recall this large and important class of integralfunctionals

J(v) =1

2

∫Ω

A(x , v)|∇v |2 +λ

2

∫Ω

v 2 −∫

Ω

f v λ > 0.

The Euler-Lagrange equation for J is (at least formally)the quasilinear elliptic problem−div(A(x , u)∇u) + 1

2A′(x , u)|∇u|2 + λ u = f in Ω,

u = 0 on ∂Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Calculus of Variations (in the study of integral functionals)

Recall this large and important class of integralfunctionals

J(v) =1

2

∫Ω

A(x , v)|∇v |2 +λ

2

∫Ω

v 2 −∫

Ω

f v λ > 0.

The Euler-Lagrange equation for J is (at least formally)the quasilinear elliptic problem−div(A(x , u)∇u) + 1

2A′(x , u)|∇u|2 + λ u = f in Ω,

u = 0 on ∂Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

Background

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

Existence [+several friends],

Existence with regularizing effect [B-Gallouet],

(L.B. dedicated to 60-Laurent).

Theorem (Weak Maximum Principle / easy )

If f ≥ 0, then the weak solution u is such that u ≥ 0almost everywhere in Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

Background

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

Existence [+several friends],

Existence with regularizing effect [B-Gallouet],

(L.B. dedicated to 60-Laurent).

Theorem (Weak Maximum Principle / easy )

If f ≥ 0, then the weak solution u is such that u ≥ 0almost everywhere in Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

Background

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

Existence [+several friends],

Existence with

regularizing effect [B-Gallouet],

(L.B. dedicated to 60-Laurent).

Theorem (Weak Maximum Principle / easy )

If f ≥ 0, then the weak solution u is such that u ≥ 0almost everywhere in Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

Background

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

Existence [+several friends],

Existence with regularizing effect [B-Gallouet],

(L.B. dedicated to 60-Laurent).

Theorem (Weak Maximum Principle / easy )

If f ≥ 0, then the weak solution u is such that u ≥ 0almost everywhere in Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

Background

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

Existence [+several friends],

Existence with regularizing effect [B-Gallouet],

(L.B. dedicated to 60-Laurent).

Theorem (Weak Maximum Principle /

easy )

If f ≥ 0, then the weak solution u is such that u ≥ 0almost everywhere in Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

Background

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

Existence [+several friends],

Existence with regularizing effect [B-Gallouet],

(L.B. dedicated to 60-Laurent).

Theorem (Weak Maximum Principle / easy

)

If f ≥ 0, then the weak solution u is such that u ≥ 0almost everywhere in Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

Background

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

Existence [+several friends],

Existence with regularizing effect [B-Gallouet],

(L.B. dedicated to 60-Laurent).

Theorem (Weak Maximum Principle / easy )

If f ≥ 0, then the weak solution u is such that u ≥ 0almost everywhere in Ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

pour Laurent

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

even with f(x) very singular

Theorem (Strong Maximum Principle)

If f ≥ 0 (and not almost everywhere equal to zero),then for every set ω ⊂⊂ Ω there exists mω > 0 such thatu(x) ≥ mω almost everywhere in ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

pour Laurent

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

even with f(x) very singular

Theorem (Strong Maximum Principle)

If f ≥ 0 (and not almost everywhere equal to zero),then for every set ω ⊂⊂ Ω there exists mω > 0 such thatu(x) ≥ mω almost everywhere in ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Second Maximum principle, dedicated to Laurent [L.B. - Luigi Orsina, Advanced Nonlinear Sudies, 2020]

Quasilinear Dirichlet problems having l.o.t. with natural growth

pour Laurent

Consider the Dirichlet problem

u ∈ W 1,20 (Ω) : −div([a(x)+|u|q]∇u)+λ u+b(x) u|u|p−1|∇u|2 = f (x)

even with f(x) very singular

Theorem (Strong Maximum Principle)

If f ≥ 0 (and not almost everywhere equal to zero),then for every set ω ⊂⊂ Ω there exists mω > 0 such thatu(x) ≥ mω almost everywhere in ω.

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Next future

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Next future

to MARIE-F. and LAURENT

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Next future

to MARIE-F. and LAURENT

je vous souhaite tous le bien

without

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Next future

to MARIE-F. and LAURENT

je vous souhaite tous le bien

without

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Next future

to MARIE-F. and LAURENT

je vous souhaite tous le bien

without

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Merci

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Merci

Thanks

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Merci

Thanks

Ciao

Marie-Francoise Daza, Laurent Ariza: El amor en los tiempos del coronavirus

Merci

Thanks

Ciao