Renormalized and entropy solutions of partial differential equations. Piotr Gwiazda
|
|
- Morgan Webster
- 5 years ago
- Views:
Transcription
1 Renormalized and entropy solutions of partial differential equations Piotr Gwiazda
2 Note on lecturer Professor Piotr Gwiazda is a recognized expert in the fields of partial differential equations, applied mathematics, and functional analysis. He has enriched his scientific experiences visiting universities in Darmstadt, Heidelberg, Berlin, Paris, Prague, Brescia and, as a consequence, he collaborates with best mathematicians from France, Germany, Italy, Czech Republic. Prof. Gwiazda defended his Ph.D. in Faculty Mathematics, Informatics and Mechanics of Warsaw University in 1999 and in 2006 got his habilitation. Currently, he is a professor in Faculty Mathematics, Informatics and Mechanics of Warsaw University. Actually, prof. Piotr Gwiazda is a coordinator of the Ph.D. Programme Mathematical Methods in Natural Sciences financed by European Regional Development Funds via the Foundation for Polish Sciences Piotr Gwiazda (Uniwersytet Warszawski) Renormalized and entropy solutions of partial differential equations For most of equations, that are significant from the point of view of mathematical physics, it is impossible to show the existence of classical solutions, ie, solutions which are continuously differentiable as many times as the order derivatives in equations under consideration. On the other hand, the concept of distribution solutions (or weak solutions) appears to be too poor and does not allow us to pose certain problems correctly. As an example, we can point out the lack of the uniqueness in the class distribution solutions to the simplest Burgers equation or other pathologies which appear in the case of distribution solutions to many partial differential equations. Hence, as a certain more general idea, we can use the notion of the entropy or the renormalization, that is to postulate that (in addition to the weak formulation of the problem) the equation satisfies certain additional weak formulation in entropic or renormalized sense (for a sufficiently rich family of entipies/renormalizations). This program (derived essentially from hyperbolic conservation laws) has found applications in many other equations: elliptic equations, parabolic equations, the Boltzmann equation, the transport equation, the Navier-Stokes equation for compressible fluid or with variable density. As another application of the entropy method, one should mention the method of relative entropy, used to analyze the long time behavior of solutions to partial differential equations. This program was successfully applied in the case of equations such as the Fokker-Planck equation, the nonlinear diffusion equation (the porous medium equation), and other equations from mathematical biology. Since this is an introductory course, we shall concentrate on the following simplest and selected issues: The Kruzkov theory entropy solutions for scalar hyperbolic equations; the DiPerny-Lions theory of renormalized solutions to the transport equation; theory of renormalized and entropy solutions to elliptic and parabolic equations; the method of relative entropy in dynamics of biological populations
3 Piotr Gwiazda Institute of Applied Mathematics and Mechanics University of Warsaw Renormalized and entropy solutions for partial differential equations Wroc law, Example 1 Cauchy problem for hyperbolic conservation law : t u(t, x) + div x F (u(t, x)) = 0 x R n, t > 0. with initial condition u(0, x) = u 0 (x). Function F : R m R n is the flux of the unknown. Problem: On one side even in the simpliest case, i.e. Burgers equation (n = m = 1, F ( ) = ( ) 2 ) the solutions with initial condition u 0 Cc in the finite time become discontinuous functions, on the other side distributional (discontinuous) solutions are not unique. Smooth initial data and discontinuous solutions u t + f(u) x = 0, u(x, 0) = u 0 (x). Consider the characteristics dt ds = 1, dx ds = f (u). The solution is constant on the characteristics, and their slope is equal to 1/f (u). If there exist x 1 < x 2 such that 1/f (u 0 (x 1 )) < 1/f (u 0 (x 2 )), then the characteristics from the points (x 1, 0) i (x 2, 0) will intersect at time t > 0. ( ) u 2 1, x 0, u t + = 0, u 0 (x) = 1 x, 0 x 1, 2 x 0, x 1.
4 Solution 1, x t, 0 t 1, 1 x u(t, x) = 1 t, t x 1, 0 t 1 0, x 1, 0 t 1. For t 1 the characteristics intersect. Example of non-uniqueness Riemanna problem for Burgers equation ( ) { u 2 1, x < 0, u t + = 0, u 0 (x) = 2 1, x > 0. x For each α 1 the problem possesses solution u α defined as follows 1 dla 2x < (1 α)t, α dla (1 α)t < 2x < 0, u α (x) = α dla 0 < 2x < (α 1)t, 1 dla (α 1)t < 2x. Observation: If (η, q) are such that u η u F = u q then the classical solution of also satisfies t u(t, x) + div x F (u(t, x)) = 0 x R n, t > 0. t η(u(t, x)) + div x q(u(t, x)) = 0 x R n, t > 0. Remark: (η, q) satisfying u η u F = u q are called entropy pair, and if additionally η is a convex function, then we call it convex entropy pair. 2
5 Definition: We say that u is a weak entropy solution to hyperbolic conservation law if it is a distributional solution and additionally t η(u(t, x)) + div x q(u(t, x)) 0 in D for each convex entropy pair (η, q). Remark: If m = 1, then there are a lot of such pairs. They are used for showing uniqueness, compactness in strong topology L p, regularity in fractional Sobolew spaces, etc. Unfortunately for m > 1 the situation becomes essentially more complicated and the reach enough family of pairs we have only in the case when m = 2 and n = 1. Motivation for the definition (Parabolic approximation) then t u ɛ (t, x) + div x F (u ɛ (t, x)) = ɛ x u ɛ (t, x) x R n, t > 0. t η(u ɛ (t, x)) + div x q(u ɛ (t, x)) = = ɛ[ x u ɛ 2 uη(u ɛ ) x u ɛ + x η(u ɛ (t, x))] x R n, t > 0. Observe that x u ɛ 2 uη(u ɛ ) x u ɛ 0 since η is convex. The maximum principle for parabolic equation provides that u ɛ u 0, so ɛ x η(u ɛ (t, x)) 0 in D for ɛ 0. Finally we obtain in the limit nonnegative distribution, namely the Radon measure. Example 2. Transport equation with a non-lipschitz coefficient. Consider the initial value problem for the transport equation t u(t, x) + b(x) xu(t, x) = 0, x R n, t > 0. Question: what regularity of the coefficient b( ) is needed to obtain the existence and uniqueness of classical solutions (i.e., differentiable functions)? Answer: b( ) should be Lipschitz functions ( x b L ). Explanation: Solving the Cauchy problem for transport equation reduces to solving the ordinary differential equation backwards for the characteristics: d X(t) = b(x(t)) with an end condition X(t) = x dt 3
6 (Thm. Picard-Lindeloef)! Recall that u(t, X(t)) solution to the transport equation is constant along characteristics. Hence the solution to transport equation can be computed from the initial condition according to the formula: u(t, x) := u(0, X(0)). Renormalized solutions DiPerna, Lions 89: 1. assume only that b W 1,1 loc and div b L, 2. we require that the solution satisfies for each β C 1, β L β(u(t, x)) + b(x) t xβ(u(t, x)) = 0 renormalization property in the distributional sense. In particular, for β(ξ) = ξ we obtain the original equation u(t, x) + b(x) t xu(t, x) = 0 3. let additionally assume, that the set of solutions is a linear space (natural demand for the linear equation) Result: In this class we obtain existence and uniqueness of solutions Question: Why the renormalization property implies the uniqueness of solutions? Explanation: Consider w = u 1 u 2 the difference of two solutions with the same initial condition. Integrating the equation w.r.t. x we obtain: d dt β(w(t, x))dx + b(x) x β(w(t, x))dx = 0. R n R n After applying the formula for integrating per parts and Höldera inequality we obtain: d β(w(t, x))dx div b L β(w(t, x))dx. dt R n R n 4
7 Due to applying β( ) = (small technical problem) and Gronwalla inequality we obtain w(t) L 1 e (t div b L ) w(0) L 1 and hence uniqueness of solutions. The idea of the proof of existnce of renormalized solutions 1. for regular solutions (of class C 1 ) of the transport equation the renormalization property is a consequence of the chain rule for the derivative of a composition (we multiply the transport equation with β (u)), 2. it is easy to show the existence of distributional solutions: approximation of b with a sequence b n W 1,, a priori estimates independent of n for the sequence u n (e.g. in the space L ), Banach-Alaoglu theorem and the property of weak star continuity of linear equations existence of distributional solutions 3. unfortunately they do not have to satisfy a priori the renormalization property (the problemem of the lack of weak star continuity of nonlinear mapping u β(u)) 4. fact: if b W 1,1 loc, u L then ϕ ɛ (b x u) b (ϕ ɛ u ) ɛ 0+ 0 w L 1 loc, where ϕ ɛ (x) := ϕ (x/ɛ) (ϕ C c ). 5. we obtain: t (ϕ ɛ u) + b x (ϕ ɛ u) = r ɛ 0+ ɛ 0 w L 1 loc, multiplying the above equation with β (ϕ ɛ u) and using the chain rule we obtain t β(ϕ ɛ u) + b x β(ϕ ɛ u) = r ɛ β (ϕ ɛ u) ɛ 0+ 0 w L 1 loc 6. recall that if u L 1 loc then ϕ ɛ u ɛ 0+ u w L 1 loc, 5
8 due to linear growth conditions β (tj. β(ξ) C(1 + ξ )) β(ϕ ɛ u) ɛ 0+ β(u) w L 1 loc, Example 3. Renormalized solutions to scalar elliptic and parabolic consider the elliptic equation div x ( x u(x) p 2 x u(x)) + div x F (u(x)) = f(x) x with the boundary condition u = 0. Difficulties: F W 1, loc (R, Rn ), and f L 1 () for p (1, n). In this situation Sobolew embedding theorem does not provide the embedding of W 1,p 0 () into L (). Hence the problem is the lack of proper growth conditions for F and the fact that f is not an element of the dual space to W 1,p 0 ()! Solution: Let us introduce the truncation operator T n, then T n (u) n. Using T n (u) as a test function in a weak formulation we obtain apriori estimate x T n (u) L p n f L 1 Definition: The function u is called the renormalized solution if T n (u) W 1,p 0 () for each n N, and moreover in the distributional sense the following equation is satisfied div x ( x u p 2 x u)β(u) + div x F (u)β(u) = fβ(u) for each function β C c (R, R n ). Question: Why all the terms appearing in the equation in the definition are well defined? Answer: Observe that if suppβ ( n, n) then it holds: div x ( x u p 2 x u)β(u) = div x ( x T n (u) p 2 x T n (u))β(t n (u)) and so div x F (u)β(u) = div x F (T n (u))β(t n (u)) div x ( x u p 2 x u)β(u) L p (), div x F (u)β(u) L p () 6
9 Example 4 Renormalized solutions for Boltzmann equation t f(t, x, v) + v x f(t, x, v) = Q[f(t, x ), f(t, x, )] where f(t, x, v)- density of particles of gas in a given time, space and velocity vector. Problem: It is possible to show only the estimates in L 1 for the bilinear collision term Q[f, f]. Solution: R. DiPerna i P.-L. Lions 89, existence of renormalized solutions for Boltzmann equation Example 5 Renormalizations in the conservation law of mass in the Naviera- Stokes system for the fluid of a nonhomogeneous density t ρ(t, x) + div x [ρ(t, x)v(t, x)] = 0 t [ρ(t, x)v(t, x)] + div x [ρ(t, x)v(t, x) v(t, x)] + x p(t, x) = x u(t, x) div x v(t, x) = 0 with an initial condition and boundary conditions (e.g. Dirichlet). Application: In a natural way div x v L, and from the total energy estimate v W 1,2 0, but it is not possible to show that v W 1,, hence using the method of renormalizations we obtain the compactness properties for ρ in a strong topology L p. More detailly, since d ρ dt L p = 0 hence showing the weak and strong convergence is the same. Example 6 Renormalizations in a mass conservation law in the Naviera-Stokes system for the compressible fluid t ρ(t, x) + div x [ρ(t, x)v(t, x)] = 0 t [ρ(t, x)v(t, x)] + div x [ρ(t, x)v(t, x) v(t, x)] + x ρ γ (t, x) = x u(t, x) with an initial condition and boundary conditions (e.g. Dirichlet). The constant γ > 1 and it is dependent on the number of degrees of freedom. For the one atomic gas it takes the discrete set of values. 7
10 Hyperbolic conservation laws - Luc Tartare Compansated compactness and Young measures Example (L.C. Young) Minimize 1 (u 2 x 1) 2 + u 2 dx subject to u(0) = u(1) = 0 0 The infimum of the functional is zero, but it cannot be attained since there is no function that satisfies u 0 and u x = ±1 almost everywhere. Minimizing sequence must oscillate and converge weakly, but not strongly, to zero. Notation C 0 (R d ) closure of the space of continuous functions on R d with compact support w.r.t. the -norm. (C 0 (R d )) = M(R d ) the space of signed Radon measures with finite mass. The duality pairing is given by µ, f = f(λ) dµ(λ). R d Definicja 1 A map µ : M(R d ) is called weakly* measurable if the functions x µ(x), f are measurable for all f C 0 (R d ). Twierdzenie 1 (Fundamental theorem on Young measures) Let R d and let z j : R d be a sequence of measurable functions. Then there exists (z j k ) and a weakly* measurable map ν : M(R d ) such that: i) ν x 0, ν x M(R d ) = R d dν x 1 for a.a. x. ii) For all f C 0 (R d ) (iii) Let K R d be compact. Then f(z j k ) f, where f(x) = ν x, f in L () 8
11 supp ν x K if dist(z j k, K) 0 in measure. iv) ν x M(R d ) = 1 for a.a. x the tightness condition is satisfied, i.e. lim sup { z j k M} = 0. M k v) Tightness condition + A is measurable, f C(R d ) and f(z j k ) is relatively weakly compact in L 1 (A), then f(z j k ) f where f(x) = ν x, f in L 1 (A). (0.1) Remark The map ν : M(R d ) is called the Young measure generated by the sequence (z j k ). Every (weakly* measurable map) ν : M(R d ) that satisfies (i) is generated by some sequence (z k ). Proof: Let Then ν j x = δ {z j (x)}. ν j x M(R d ) = 1 and ν j x, f = f(z j (x)) ν j is bounded in L w (; M(R d )) - the space of weakly* measurable maps µ : M(R d ) that are essentially bounded. Note that with the duality pairing Banach Alaoglu L w (; M(R d )) = ( L 1 (; C 0 (R d )) ) µ, g = µ x, g dx. ν j k ν in L w (; M(R d )) (0.2) Lower semicontinuity of the norm provides ν x M(R d ) 1. (0.2) means that for all ψ L 1 (; C 0 (R d )) ψ(x, z j k (x))dx = ν x, ψ(x, ) dx. Choose lim k ψ(x, λ) = ϕ(x)f(λ) 9
12 where ϕ L 1 () and f C 0 (R d ). Thus f(z j k ) ν x, f in L (). Let 1 λ M T M (λ) = 1 + M λ M λ M λ M + 1 Then Observe that which means that so Let M lim T M (z j k (x))dx = lim T k k M (λ)dδ {z j k (x)} dx R d = ν x, T M dx ν x, 1 dx = ν x M(R )dx d (1 T M (z j k (x)))dx { z j k M} { z j k M} T M (z j k (x))dx sup { z j k M} ν x M(R )dx. d k N ν x M(R )dx. d Hence ν x is a probability measure a.e. Generalized Jensen s inequality Let g : R d R d be strictly convex, µ - a probability measure on R d with compact support. Then µ, g g( µ, Id ), (0.3) with equality occurring if and only if µ is a Dirac measure. Lemat 2 z j : R d generates the Young measure ν. Then z j z in measure ν x = δ z(x) a.e. 10
13 Proof: ( ) If z j z in measure, then for all f C 0 (R d ) f(z j ) f(z) in measure. By Theorem 1 (ii) ν x, f = f(z(x)) = δ {z(x)}, f for all f C 0 (R d ) and thus ν x = δ {z(x)}. Then Example: Scalar conservation law t u + x f(u) = 0 Let (η, q) be the entropy-entropy flux pair {u k (x, t)} a bounded sequence in L () t η(u k ) + x q(u k ) compact set in W 1,2 loc (). u k u and f(u k ) f(u) in L f(u)? = f(u) Div-curl lemma Let R d and U j U in L 2 (), V j V in L 2 () div U j and curl V j compact set in W 1,2 (). Then U j V j U V in D (). Consider two entropy-entropy flux pairs (η 1, q 1 ), (η 2, q 2 ). Notice that div (q 2 (u k ), η 2 (u k )), curl (η 1 (u k ), q 1 (u k )) compact set of W 1,2 11
14 Use div-curl lemma and characterization of the limit to conclude ν, η 1 ν, q 2 ν, η 2 ν, q 1 = ν, η 1 q 2 η 2 q 1 Applying some algebraic inequalities we obtain [ ν, f f(u)] 2 0 hence ν, f = f(u). If f is strictly convex, then generalized Jensen s inequality (0.3) provides that ν is a Dirac measure. Method of doubling the variables We consider the equation t u + F (u) = 0, (0.4) x We will introduce the class of weak entropy solutions, which is the appropriate one for the above system. Definicja 2 Suppose that η = η(u), q = q(u) are scalar C 1 -functions and F (u) is a C 1 -function, satisfying u η(u) u F (u) = u q(u). Such functions (η, q) are called entropy-entropy flux pair for the system (0.4). If η is convex, then (η, q) is called a convex entropy-entropy flux pair. Definicja 3 We call u L ([0, T ) R; R) a weak entropy solution to with the initial data u 0 L (R; R) iff t u + t F (u) = 0 1. u is a weak solution, i.e. [ u(t, x) ] t ψ(t, x) + F (u(t, x)) ψ(t, x) dtdx x [0,T ) R + u 0 (x) ψ(0, x)dx = 0 for all test functions ψ C 1 c ([0, T ) R; R). R 12
15 2. The entropy inequality [0,T ) R [η(u(t, x)) φ(t, x) + q(u(t, x)) t x + R φ(t, x)] dtdx η(u 0 (x))φ(0, x)dx 0 holds for all nonnegative test functions φ C 1 c ([0, T ) R; R) and all convex entropyentropy flux pairs (η, q). Remark The above definition is standard in the theory of conservation laws. Twierdzenie 3 Let u, u C 0 ([0, T ); L 1 loc (R; R)) L ([0, T ) R; R) be two weak entropy solutions to (0.4) with (u u) L ([0, T ); L 1 (R; R)) and initial data u 0, u 0 L (R; R). Then for any 0 < t < T it holds u(t) u(t) L 1 (R) u 0 u 0 L 1 (R) Proof Henceforth η δ (w, w) defined below, becomes an entropy function, q δ (w, w) denotes a corresponding entropy flux, where u is a parameter taking values in R, i = 1, 2 η δ (u, u) = 0 for u u (u u) 2 4δ for u < u u + 2δ u u δ for u > u + 2δ. Note that and 0 for u u u u u η δ (u, u) = for u < u u + 2δ 2δ 1 for u > u + 2δ 0 for u u u η δ (u, u) = u u for u < u u + 2δ 2δ 1 for u > u + 2δ,. 13
16 To the entropy inequality as a test function we can insert nonnegative function φ(t, x, t, x) Cc 1 (((0, T ) R) 2, R). Then for some fixed (t, x) the inequality takes the form { t φ(t, x, t, x)η δ(u, u) + x φ(t, x, t, x)q δ (u, u)}dtdx 0 [0,T ) R In the same manner with (t, x) fixed, the following inequality can be obtained { t φ(t, x, t, x)η δ(u, u) + x φ(t, x, t, x)q δ(u, u)}dtdx 0 [0,T ) R Integrating the first inequality with respect to (t, x) and the second with respect to (t, x), then adding them leads to the following result t + t )φ(t, x, t, x)η δ(u, u) ([0,T ) R) 2 {( +( x + x )φ(t, x, t, x)q δ(u, u)}dtdxdtdx 0 (0.5) We fix a smooth, compactly supported function ξ : R R + satisfying ξ(x)dx = 1 R and we choose as a test function in (0.5) φ(t, x, t, x) = 1 ( t + t ɛ ψ 2 2, x + x ) ( ) ( ) t t x x ξ ξ, 2 2ɛ 2ɛ where ψ : R R + R + is a C 1 -function with a compact support (supp(ψ) ((0, T ) R) 2 ). Note that ( t + t )φ(t, x, t, x) = 1 ( t + t ɛ 2 t ψ 2, x + x ) ( ) ( ) t t x x ξ ξ 2 2ɛ 2ɛ and ( x + x )φ(t, x, t, x) = 1 ( t + t ɛ 2 x ψ 2, x + x ) ξ 2 ( t t 2ɛ ) ξ ( x x Letting ɛ 0 we find that the inequality (0.5) yields to (for more details on this step we refer the reader to [1]) { t ψ(t, x)η δ(u, u)+ x ψ(t, x)q δ(u, u)}dtdx 0 (0.6) [0,T ) R 14 2ɛ ).
17 for all nonnegative C 1 -functions ψ with a compact support in (0, T ) R. Density of the space Cc 1 ((0, T ) R; R) in W 1,1 0 ([0, T ) R; R), together with the fact that u, u L ([0, T ) R; R) imply the above inequality holds also for ψ W 1,1 0 ([0, T ) R; R). Therefore we use as a test function ψ(t, x) = ζ r (x)θ ɛ,s (t) where 0 x > r + 1 ζ r (x) = r + 1 x r < x < r + 1 (0.7) 1 x < r and θ ɛ,s (t) = 0 0 < t s or t > τ + ɛ 1 s + ɛ < t τ 1 t s ɛ ɛ 1t τ ɛ ɛ s < t s + ɛ τ < t τ + ɛ (0.8) for r > 0, 0 < s < τ, 0 < ɛ < τ ɛ. 1 ɛ r r τ+ɛ τ η δ (u, u)dtdx 1 ɛ {r< x <r+1} s τ+ɛ θ ɛ,s (t)q δ (u, u)dtdx 1 ɛ r r s+ɛ s η δ (u, u)dtdx Let first s 0, and then ɛ 0. Using in both cases continuity with respect to t (i.e. u, u C 0 ([0, T ); L 1 loc (R; R))) we conclude that r η δ (u, u)dx τ q δ (u, u)dxdt (r+1) η δ (u 0, u 0 )dx r 0 {r< x <r+1} (r+1) for all t [0, T ). Letting first δ 0, and then r we conclude with standard dominated Lebesgue convergence theorem argument {[u(τ, x) u(τ, x)] + {[u 0 (x) u 0 (x)] + R R Interchanging u with u leads to the analogous inequality. Adding both inequalities yields the assertion of the theorem. 15
18 References [1] Kruzkov, S., First-order quasilinear equations with several space variables Mat. Sbornik 123 (1970), English translation: Math. USSR Sbornik 10 (1970),
Measure-valued - strong uniqueness for hyperbolic systems
Measure-valued - strong uniqueness for hyperbolic systems joint work with Tomasz Debiec, Eduard Feireisl, Ondřej Kreml, Agnieszka Świerczewska-Gwiazda and Emil Wiedemann Institute of Mathematics Polish
More informationDifferentiability with respect to initial data for a scalar conservation law
Differentiability with respect to initial data for a scalar conservation law François BOUCHUT François JAMES Abstract We linearize a scalar conservation law around an entropy initial datum. The resulting
More informationLECTURE # 0 BASIC NOTATIONS AND CONCEPTS IN THE THEORY OF PARTIAL DIFFERENTIAL EQUATIONS (PDES)
LECTURE # 0 BASIC NOTATIONS AND CONCEPTS IN THE THEORY OF PARTIAL DIFFERENTIAL EQUATIONS (PDES) RAYTCHO LAZAROV 1 Notations and Basic Functional Spaces Scalar function in R d, d 1 will be denoted by u,
More informationEXISTENCE AND REGULARITY RESULTS FOR SOME NONLINEAR PARABOLIC EQUATIONS
EXISTECE AD REGULARITY RESULTS FOR SOME OLIEAR PARABOLIC EUATIOS Lucio BOCCARDO 1 Andrea DALL AGLIO 2 Thierry GALLOUËT3 Luigi ORSIA 1 Abstract We prove summability results for the solutions of nonlinear
More informationON WEAKLY NONLINEAR BACKWARD PARABOLIC PROBLEM
ON WEAKLY NONLINEAR BACKWARD PARABOLIC PROBLEM OLEG ZUBELEVICH DEPARTMENT OF MATHEMATICS THE BUDGET AND TREASURY ACADEMY OF THE MINISTRY OF FINANCE OF THE RUSSIAN FEDERATION 7, ZLATOUSTINSKY MALIY PER.,
More informationFractal Conservation Laws: Global Smooth Solutions and Vanishing Regularization
Progress in Nonlinear Differential Equations and Their Applications, Vol. 63, 217 224 c 2005 Birkhäuser Verlag Basel/Switzerland Fractal Conservation Laws: Global Smooth Solutions and Vanishing Regularization
More informationNonlinear Regularizing Effects for Hyperbolic Conservation Laws
Nonlinear Regularizing Effects for Hyperbolic Conservation Laws Ecole Polytechnique Centre de Mathématiques Laurent Schwartz Collège de France, séminaire EDP, 4 mai 2012 Motivation Consider Cauchy problem
More informationFormulation of the problem
TOPICAL PROBLEMS OF FLUID MECHANICS DOI: https://doi.org/.43/tpfm.27. NOTE ON THE PROBLEM OF DISSIPATIVE MEASURE-VALUED SOLUTIONS TO THE COMPRESSIBLE NON-NEWTONIAN SYSTEM H. Al Baba, 2, M. Caggio, B. Ducomet
More informationWeak-Strong Uniqueness of the Navier-Stokes-Smoluchowski System
Weak-Strong Uniqueness of the Navier-Stokes-Smoluchowski System Joshua Ballew University of Maryland College Park Applied PDE RIT March 4, 2013 Outline Description of the Model Relative Entropy Weakly
More informationON COMPARISON PRINCIPLES FOR
Monografías Matemáticas García de Galdeano 39, 177 185 (214) ON COMPARISON PRINCIPLES FOR WEAK SOLUTIONS OF DOUBLY NONLINEAR REACTION-DIFFUSION EQUATIONS Jochen Merker and Aleš Matas Abstract. The weak
More informationHyperbolic Systems of Conservation Laws. in One Space Dimension. I - Basic concepts. Alberto Bressan. Department of Mathematics, Penn State University
Hyperbolic Systems of Conservation Laws in One Space Dimension I - Basic concepts Alberto Bressan Department of Mathematics, Penn State University http://www.math.psu.edu/bressan/ 1 The Scalar Conservation
More informationThe incompressible Navier-Stokes equations in vacuum
The incompressible, Université Paris-Est Créteil Piotr Bogus law Mucha, Warsaw University Journées Jeunes EDPistes 218, Institut Elie Cartan, Université de Lorraine March 23th, 218 Incompressible Navier-Stokes
More informationSECOND ORDER TIME DISCONTINUOUS GALERKIN METHOD FOR NONLINEAR CONVECTION-DIFFUSION PROBLEMS
Proceedings of ALGORITMY 2009 pp. 1 10 SECOND ORDER TIME DISCONTINUOUS GALERKIN METHOD FOR NONLINEAR CONVECTION-DIFFUSION PROBLEMS MILOSLAV VLASÁK Abstract. We deal with a numerical solution of a scalar
More informationCONVERGENCE THEORY. G. ALLAIRE CMAP, Ecole Polytechnique. 1. Maximum principle. 2. Oscillating test function. 3. Two-scale convergence
1 CONVERGENCE THEOR G. ALLAIRE CMAP, Ecole Polytechnique 1. Maximum principle 2. Oscillating test function 3. Two-scale convergence 4. Application to homogenization 5. General theory H-convergence) 6.
More informationNew York Journal of Mathematics. A Refinement of Ball s Theorem on Young Measures
New York Journal of Mathematics New York J. Math. 3 (1997) 48 53. A Refinement of Ball s Theorem on Young Measures Norbert Hungerbühler Abstract. For a sequence u j : R n R m generating the Young measure
More informationConvergence of Finite Volumes schemes for an elliptic-hyperbolic system with boundary conditions
Convergence of Finite Volumes schemes for an elliptic-hyperbolic system with boundary conditions Marie Hélène Vignal UMPA, E.N.S. Lyon 46 Allée d Italie 69364 Lyon, Cedex 07, France abstract. We are interested
More informationLocal null controllability of the N-dimensional Navier-Stokes system with N-1 scalar controls in an arbitrary control domain
Local null controllability of the N-dimensional Navier-Stokes system with N-1 scalar controls in an arbitrary control domain Nicolás Carreño Université Pierre et Marie Curie-Paris 6 UMR 7598 Laboratoire
More informationApplied Math Qualifying Exam 11 October Instructions: Work 2 out of 3 problems in each of the 3 parts for a total of 6 problems.
Printed Name: Signature: Applied Math Qualifying Exam 11 October 2014 Instructions: Work 2 out of 3 problems in each of the 3 parts for a total of 6 problems. 2 Part 1 (1) Let Ω be an open subset of R
More informationPartial Differential Equations
Part II Partial Differential Equations Year 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2015 Paper 4, Section II 29E Partial Differential Equations 72 (a) Show that the Cauchy problem for u(x,
More informationEuler Equations: local existence
Euler Equations: local existence Mat 529, Lesson 2. 1 Active scalars formulation We start with a lemma. Lemma 1. Assume that w is a magnetization variable, i.e. t w + u w + ( u) w = 0. If u = Pw then u
More informationRelation between Distributional and Leray-Hopf Solutions to the Navier-Stokes Equations
Relation between Distributional and Leray-Hopf Solutions to the Navier-Stokes Equations Giovanni P. Galdi Department of Mechanical Engineering & Materials Science and Department of Mathematics University
More informationConservation law equations : problem set
Conservation law equations : problem set Luis Silvestre For Isaac Neal and Elia Portnoy in the 2018 summer bootcamp 1 Method of characteristics For the problems in this section, assume that the solutions
More informationOn some nonlinear parabolic equation involving variable exponents
On some nonlinear parabolic equation involving variable exponents Goro Akagi (Kobe University, Japan) Based on a joint work with Giulio Schimperna (Pavia Univ., Italy) Workshop DIMO-2013 Diffuse Interface
More informationUniversität des Saarlandes. Fachrichtung 6.1 Mathematik
Universität des Saarlandes U N I V E R S I T A S S A R A V I E N I S S Fachrichtung 6.1 Mathematik Preprint Nr. 155 A posteriori error estimates for stationary slow flows of power-law fluids Michael Bildhauer,
More informationOn a Lyapunov Functional Relating Shortening Curves and Viscous Conservation Laws
On a Lyapunov Functional Relating Shortening Curves and Viscous Conservation Laws Stefano Bianchini and Alberto Bressan S.I.S.S.A., Via Beirut 4, Trieste 34014 Italy. E-mail addresses: bianchin@mis.mpg.de,
More informationASYMPTOTIC BEHAVIOUR OF NONLINEAR ELLIPTIC SYSTEMS ON VARYING DOMAINS
ASYMPTOTIC BEHAVIOUR OF NONLINEAR ELLIPTIC SYSTEMS ON VARYING DOMAINS Juan CASADO DIAZ ( 1 ) Adriana GARRONI ( 2 ) Abstract We consider a monotone operator of the form Au = div(a(x, Du)), with R N and
More informationBIHARMONIC WAVE MAPS INTO SPHERES
BIHARMONIC WAVE MAPS INTO SPHERES SEBASTIAN HERR, TOBIAS LAMM, AND ROLAND SCHNAUBELT Abstract. A global weak solution of the biharmonic wave map equation in the energy space for spherical targets is constructed.
More informationGENERATORS WITH INTERIOR DEGENERACY ON SPACES OF L 2 TYPE
Electronic Journal of Differential Equations, Vol. 22 (22), No. 89, pp. 3. ISSN: 72-669. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu ftp ejde.math.txstate.edu GENERATORS WITH INTERIOR
More informationb i (µ, x, s) ei ϕ(x) µ s (dx) ds (2) i=1
NONLINEAR EVOLTION EQATIONS FOR MEASRES ON INFINITE DIMENSIONAL SPACES V.I. Bogachev 1, G. Da Prato 2, M. Röckner 3, S.V. Shaposhnikov 1 The goal of this work is to prove the existence of a solution to
More informationFrom Boltzmann Equations to Gas Dynamics: From DiPerna-Lions to Leray
From Boltzmann Equations to Gas Dynamics: From DiPerna-Lions to Leray C. David Levermore Department of Mathematics and Institute for Physical Science and Technology University of Maryland, College Park
More information2 Statement of the problem and assumptions
Mathematical Notes, 25, vol. 78, no. 4, pp. 466 48. Existence Theorem for Optimal Control Problems on an Infinite Time Interval A.V. Dmitruk and N.V. Kuz kina We consider an optimal control problem on
More informationContents: 1. Minimization. 2. The theorem of Lions-Stampacchia for variational inequalities. 3. Γ -Convergence. 4. Duality mapping.
Minimization Contents: 1. Minimization. 2. The theorem of Lions-Stampacchia for variational inequalities. 3. Γ -Convergence. 4. Duality mapping. 1 Minimization A Topological Result. Let S be a topological
More informationEXISTENCE OF SOLUTIONS TO THE CAHN-HILLIARD/ALLEN-CAHN EQUATION WITH DEGENERATE MOBILITY
Electronic Journal of Differential Equations, Vol. 216 216), No. 329, pp. 1 22. ISSN: 172-6691. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu EXISTENCE OF SOLUTIONS TO THE CAHN-HILLIARD/ALLEN-CAHN
More informationAN OVERVIEW ON SOME RESULTS CONCERNING THE TRANSPORT EQUATION AND ITS APPLICATIONS TO CONSERVATION LAWS
AN OVERVIEW ON SOME RESULTS CONCERNING THE TRANSPORT EQUATION AND ITS APPLICATIONS TO CONSERVATION LAWS GIANLUCA CRIPPA AND LAURA V. SPINOLO Abstract. We provide an informal overview on the theory of transport
More informationConvergence of generalized entropy minimizers in sequences of convex problems
Proceedings IEEE ISIT 206, Barcelona, Spain, 2609 263 Convergence of generalized entropy minimizers in sequences of convex problems Imre Csiszár A Rényi Institute of Mathematics Hungarian Academy of Sciences
More informationVariational and Topological methods : Theory, Applications, Numerical Simulations, and Open Problems 6-9 June 2012, Northern Arizona University
Variational and Topological methods : Theory, Applications, Numerical Simulations, and Open Problems 6-9 June 22, Northern Arizona University Some methods using monotonicity for solving quasilinear parabolic
More informationVariable Exponents Spaces and Their Applications to Fluid Dynamics
Variable Exponents Spaces and Their Applications to Fluid Dynamics Martin Rapp TU Darmstadt November 7, 213 Martin Rapp (TU Darmstadt) Variable Exponent Spaces November 7, 213 1 / 14 Overview 1 Variable
More informationVelocity averaging, kinetic formulations and regularizing effects in conservation laws and related PDEs. Eitan Tadmor. University of Maryland
Velocity averaging, kinetic formulations and regularizing effects in conservation laws and related PDEs Eitan Tadmor Center for Scientific Computation and Mathematical Modeling (CSCAMM) Department of Mathematics,
More informationSingularities and Laplacians in Boundary Value Problems for Nonlinear Ordinary Differential Equations
Singularities and Laplacians in Boundary Value Problems for Nonlinear Ordinary Differential Equations Irena Rachůnková, Svatoslav Staněk, Department of Mathematics, Palacký University, 779 OLOMOUC, Tomkova
More informationLecture Notes on Hyperbolic Conservation Laws
Lecture Notes on Hyperbolic Conservation Laws Alberto Bressan Department of Mathematics, Penn State University, University Park, Pa. 16802, USA. bressan@math.psu.edu May 21, 2009 Abstract These notes provide
More informationSome lecture notes for Math 6050E: PDEs, Fall 2016
Some lecture notes for Math 65E: PDEs, Fall 216 Tianling Jin December 1, 216 1 Variational methods We discuss an example of the use of variational methods in obtaining existence of solutions. Theorem 1.1.
More informationNumerical methods for conservation laws with a stochastically driven flux
Numerical methods for conservation laws with a stochastically driven flux Håkon Hoel, Kenneth Karlsen, Nils Henrik Risebro, Erlend Briseid Storrøsten Department of Mathematics, University of Oslo, Norway
More informationVariational formulation of entropy solutions for nonlinear conservation laws
Variational formulation of entropy solutions for nonlinear conservation laws Eitan Tadmor 1 Center for Scientific Computation and Mathematical Modeling CSCAMM) Department of Mathematics, Institute for
More informationStrongly nonlinear parabolic initial-boundary value problems in Orlicz spaces
2002-Fez conference on Partial Differential Equations, Electronic Journal of Differential Equations, Conference 09, 2002, pp 203 220. http://ejde.math.swt.edu or http://ejde.math.unt.edu ftp ejde.math.swt.edu
More informationWELL-POSEDNESS FOR HYPERBOLIC PROBLEMS (0.2)
WELL-POSEDNESS FOR HYPERBOLIC PROBLEMS We will use the familiar Hilbert spaces H = L 2 (Ω) and V = H 1 (Ω). We consider the Cauchy problem (.1) c u = ( 2 t c )u = f L 2 ((, T ) Ω) on [, T ] Ω u() = u H
More informationFluid Approximations from the Boltzmann Equation for Domains with Boundary
Fluid Approximations from the Boltzmann Equation for Domains with Boundary C. David Levermore Department of Mathematics and Institute for Physical Science and Technology University of Maryland, College
More informationGLOBAL EXISTENCE OF SOLUTIONS TO A HYPERBOLIC-PARABOLIC SYSTEM
PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY Volume 35, Number 4, April 7, Pages 7 7 S -99396)8773-9 Article electronically published on September 8, 6 GLOBAL EXISTENCE OF SOLUTIONS TO A HYPERBOLIC-PARABOLIC
More informationOn uniqueness of weak solutions to transport equation with non-smooth velocity field
On uniqueness of weak solutions to transport equation with non-smooth velocity field Paolo Bonicatto Abstract Given a bounded, autonomous vector field b: R d R d, we study the uniqueness of bounded solutions
More informationEXISTENCE OF SOLUTIONS FOR A RESONANT PROBLEM UNDER LANDESMAN-LAZER CONDITIONS
Electronic Journal of Differential Equations, Vol. 2008(2008), No. 98, pp. 1 10. ISSN: 1072-6691. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu ftp ejde.math.txstate.edu (login: ftp) EXISTENCE
More informationOn semilinear elliptic equations with measure data
On semilinear elliptic equations with measure data Andrzej Rozkosz (joint work with T. Klimsiak) Nicolaus Copernicus University (Toruń, Poland) Controlled Deterministic and Stochastic Systems Iasi, July
More informationVelocity averaging a general framework
Outline Velocity averaging a general framework Martin Lazar BCAM ERC-NUMERIWAVES Seminar May 15, 2013 Joint work with D. Mitrović, University of Montenegro, Montenegro Outline Outline 1 2 L p, p >= 2 setting
More informationATTRACTORS FOR SEMILINEAR PARABOLIC PROBLEMS WITH DIRICHLET BOUNDARY CONDITIONS IN VARYING DOMAINS. Emerson A. M. de Abreu Alexandre N.
ATTRACTORS FOR SEMILINEAR PARABOLIC PROBLEMS WITH DIRICHLET BOUNDARY CONDITIONS IN VARYING DOMAINS Emerson A. M. de Abreu Alexandre N. Carvalho Abstract Under fairly general conditions one can prove that
More informationFunctional Analysis. Franck Sueur Metric spaces Definitions Completeness Compactness Separability...
Functional Analysis Franck Sueur 2018-2019 Contents 1 Metric spaces 1 1.1 Definitions........................................ 1 1.2 Completeness...................................... 3 1.3 Compactness......................................
More informationOn a parabolic-hyperbolic system for contact inhibition of cell growth
On a parabolic-hyperbolic system for contact inhibition of cell growth M. Bertsch 1, D. Hilhorst 2, H. Izuhara 3, M. Mimura 3, T. Wakasa 4 1 IAC, CNR, Rome 2 University of Paris-Sud 11 3 Meiji University
More informationGlobal Solutions for a Nonlinear Wave Equation with the p-laplacian Operator
Global Solutions for a Nonlinear Wave Equation with the p-laplacian Operator Hongjun Gao Institute of Applied Physics and Computational Mathematics 188 Beijing, China To Fu Ma Departamento de Matemática
More informationTHE STOKES SYSTEM R.E. SHOWALTER
THE STOKES SYSTEM R.E. SHOWALTER Contents 1. Stokes System 1 Stokes System 2 2. The Weak Solution of the Stokes System 3 3. The Strong Solution 4 4. The Normal Trace 6 5. The Mixed Problem 7 6. The Navier-Stokes
More information1. INTRODUCTION 2. PROBLEM FORMULATION ROMAI J., 6, 2(2010), 1 13
Contents 1 A product formula approach to an inverse problem governed by nonlinear phase-field transition system. Case 1D Tommaso Benincasa, Costică Moroşanu 1 v ROMAI J., 6, 2(21), 1 13 A PRODUCT FORMULA
More informationOn the local well-posedness of compressible viscous flows with bounded density
On the local well-posedness of compressible viscous flows with bounded density Marius Paicu University of Bordeaux joint work with Raphaël Danchin and Francesco Fanelli Mathflows 2018, Porquerolles September
More informationAN EXAMPLE OF FUNCTIONAL WHICH IS WEAKLY LOWER SEMICONTINUOUS ON W 1,p FOR EVERY p > 2 BUT NOT ON H0
AN EXAMPLE OF FUNCTIONAL WHICH IS WEAKLY LOWER SEMICONTINUOUS ON W,p FOR EVERY p > BUT NOT ON H FERNANDO FARRONI, RAFFAELLA GIOVA AND FRANÇOIS MURAT Abstract. In this note we give an example of functional
More informationExistence of global weak solutions to implicitly constituted kinetic models of incompressible homogeneous dilute polymers
1 / 31 Existence of global weak solutions to implicitly constituted kinetic models of incompressible homogeneous dilute polymers Endre Süli Mathematical Institute, University of Oxford joint work with
More informationIntroduction. Christophe Prange. February 9, This set of lectures is motivated by the following kind of phenomena:
Christophe Prange February 9, 206 This set of lectures is motivated by the following kind of phenomena: sin(x/ε) 0, while sin 2 (x/ε) /2. Therefore the weak limit of the product is in general different
More informationP(E t, Ω)dt, (2) 4t has an advantage with respect. to the compactly supported mollifiers, i.e., the function W (t)f satisfies a semigroup law:
Introduction Functions of bounded variation, usually denoted by BV, have had and have an important role in several problems of calculus of variations. The main features that make BV functions suitable
More informationOn a Nonlocal Elliptic System of p-kirchhoff-type Under Neumann Boundary Condition
On a Nonlocal Elliptic System of p-kirchhoff-type Under Neumann Boundary Condition Francisco Julio S.A Corrêa,, UFCG - Unidade Acadêmica de Matemática e Estatística, 58.9-97 - Campina Grande - PB - Brazil
More informationOn non negative solutions of some quasilinear elliptic inequalities
On non negative solutions of some quasilinear elliptic inequalities Lorenzo D Ambrosio and Enzo Mitidieri September 28 2006 Abstract Let f : R R be a continuous function. We prove that under some additional
More informationBose-Einstein Condensation and Global Dynamics of Solutions to a Hyperbolic Kompaneets Equation
Bose-Einstein Condensation and Global Dynamics of Solutions to a Hyperbolic Kompaneets Equation Joshua Ballew Abstract In this article, a simplified, hyperbolic model of the non-linear, degenerate parabolic
More informationt y n (s) ds. t y(s) ds, x(t) = x(0) +
1 Appendix Definition (Closed Linear Operator) (1) The graph G(T ) of a linear operator T on the domain D(T ) X into Y is the set (x, T x) : x D(T )} in the product space X Y. Then T is closed if its graph
More informationNONTRIVIAL SOLUTIONS TO INTEGRAL AND DIFFERENTIAL EQUATIONS
Fixed Point Theory, Volume 9, No. 1, 28, 3-16 http://www.math.ubbcluj.ro/ nodeacj/sfptcj.html NONTRIVIAL SOLUTIONS TO INTEGRAL AND DIFFERENTIAL EQUATIONS GIOVANNI ANELLO Department of Mathematics University
More informationOBSERVABILITY INEQUALITY AND DECAY RATE FOR WAVE EQUATIONS WITH NONLINEAR BOUNDARY CONDITIONS
Electronic Journal of Differential Equations, Vol. 27 (27, No. 6, pp. 2. ISSN: 72-669. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu OBSERVABILITY INEQUALITY AND DECAY RATE FOR WAVE EQUATIONS
More informationat time t, in dimension d. The index i varies in a countable set I. We call configuration the family, denoted generically by Φ: U (x i (t) x j (t))
Notations In this chapter we investigate infinite systems of interacting particles subject to Newtonian dynamics Each particle is characterized by its position an velocity x i t, v i t R d R d at time
More informationReal Analysis, 2nd Edition, G.B.Folland Elements of Functional Analysis
Real Analysis, 2nd Edition, G.B.Folland Chapter 5 Elements of Functional Analysis Yung-Hsiang Huang 5.1 Normed Vector Spaces 1. Note for any x, y X and a, b K, x+y x + y and by ax b y x + b a x. 2. It
More informationThe Navier-Stokes Equations with Time Delay. Werner Varnhorn. Faculty of Mathematics University of Kassel, Germany
The Navier-Stokes Equations with Time Delay Werner Varnhorn Faculty of Mathematics University of Kassel, Germany AMS: 35 (A 35, D 5, K 55, Q 1), 65 M 1, 76 D 5 Abstract In the present paper we use a time
More informationApplied Analysis (APPM 5440): Final exam 1:30pm 4:00pm, Dec. 14, Closed books.
Applied Analysis APPM 44: Final exam 1:3pm 4:pm, Dec. 14, 29. Closed books. Problem 1: 2p Set I = [, 1]. Prove that there is a continuous function u on I such that 1 ux 1 x sin ut 2 dt = cosx, x I. Define
More informationUNCERTAINTY FUNCTIONAL DIFFERENTIAL EQUATIONS FOR FINANCE
Surveys in Mathematics and its Applications ISSN 1842-6298 (electronic), 1843-7265 (print) Volume 5 (2010), 275 284 UNCERTAINTY FUNCTIONAL DIFFERENTIAL EQUATIONS FOR FINANCE Iuliana Carmen Bărbăcioru Abstract.
More informationWeak solutions and blow-up for wave equations of p-laplacian type with supercritical sources
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Faculty Publications, Department of Mathematics Mathematics, Department of 1 Weak solutions and blow-up for wave equations
More informationRegularity and compactness for the DiPerna Lions flow
Regularity and compactness for the DiPerna Lions flow Gianluca Crippa 1 and Camillo De Lellis 2 1 Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy. g.crippa@sns.it 2 Institut für Mathematik,
More informationEXISTENCE RESULTS FOR OPERATOR EQUATIONS INVOLVING DUALITY MAPPINGS VIA THE MOUNTAIN PASS THEOREM
EXISTENCE RESULTS FOR OPERATOR EQUATIONS INVOLVING DUALITY MAPPINGS VIA THE MOUNTAIN PASS THEOREM JENICĂ CRÎNGANU We derive existence results for operator equations having the form J ϕu = N f u, by using
More informationTools from Lebesgue integration
Tools from Lebesgue integration E.P. van den Ban Fall 2005 Introduction In these notes we describe some of the basic tools from the theory of Lebesgue integration. Definitions and results will be given
More informationA nonlinear cross-diffusion system for contact inhibition of cell growth
A nonlinear cross-diffusion system for contact inhibition of cell growth M. Bertsch 1, D. Hilhorst 2, H. Izuhara 3, M. Mimura 3 1 IAC, CNR, Rome 2 University of Paris-Sud 11 3 Meiji University FBP 2012
More informationHigh order geometric smoothness for conservation laws
High order geometric smoothness for conservation laws Martin Campos-Pinto, Albert Cohen, and Pencho Petrushev Abstract The smoothness of the solutions of 1D scalar conservation laws is investigated and
More informationA generalised Ladyzhenskaya inequality and a coupled parabolic-elliptic problem
A generalised Ladyzhenskaya inequality and a coupled parabolic-elliptic problem Dave McCormick joint work with James Robinson and José Rodrigo Mathematics and Statistics Centre for Doctoral Training University
More informationNONLINEAR FREDHOLM ALTERNATIVE FOR THE p-laplacian UNDER NONHOMOGENEOUS NEUMANN BOUNDARY CONDITION
Electronic Journal of Differential Equations, Vol. 2016 (2016), No. 210, pp. 1 7. ISSN: 1072-6691. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu NONLINEAR FREDHOLM ALTERNATIVE FOR THE p-laplacian
More informationEXISTENCE OF THREE WEAK SOLUTIONS FOR A QUASILINEAR DIRICHLET PROBLEM. Saeid Shokooh and Ghasem A. Afrouzi. 1. Introduction
MATEMATIČKI VESNIK MATEMATIQKI VESNIK 69 4 (217 271 28 December 217 research paper originalni nauqni rad EXISTENCE OF THREE WEAK SOLUTIONS FOR A QUASILINEAR DIRICHLET PROBLEM Saeid Shokooh and Ghasem A.
More informationGlobal Maxwellians over All Space and Their Relation to Conserved Quantites of Classical Kinetic Equations
Global Maxwellians over All Space and Their Relation to Conserved Quantites of Classical Kinetic Equations C. David Levermore Department of Mathematics and Institute for Physical Science and Technology
More informationWeek 01 : Introduction. A usually formal statement of the equality or equivalence of mathematical or logical expressions
1. What are partial differential equations. An equation: Week 01 : Introduction Marriam-Webster Online: A usually formal statement of the equality or equivalence of mathematical or logical expressions
More informationu xx + u yy = 0. (5.1)
Chapter 5 Laplace Equation The following equation is called Laplace equation in two independent variables x, y: The non-homogeneous problem u xx + u yy =. (5.1) u xx + u yy = F, (5.) where F is a function
More informationSecond order forward-backward dynamical systems for monotone inclusion problems
Second order forward-backward dynamical systems for monotone inclusion problems Radu Ioan Boţ Ernö Robert Csetnek March 6, 25 Abstract. We begin by considering second order dynamical systems of the from
More informationTHEOREMS, ETC., FOR MATH 515
THEOREMS, ETC., FOR MATH 515 Proposition 1 (=comment on page 17). If A is an algebra, then any finite union or finite intersection of sets in A is also in A. Proposition 2 (=Proposition 1.1). For every
More informationWeak Convergence Methods for Energy Minimization
Weak Convergence Methods for Energy Minimization Bo Li Department of Mathematics University of California, San Diego E-mail: bli@math.ucsd.edu June 3, 2007 Introduction This compact set of notes present
More informationTRAVELING WAVES IN 2D REACTIVE BOUSSINESQ SYSTEMS WITH NO-SLIP BOUNDARY CONDITIONS
TRAVELING WAVES IN 2D REACTIVE BOUSSINESQ SYSTEMS WITH NO-SLIP BOUNDARY CONDITIONS PETER CONSTANTIN, MARTA LEWICKA AND LENYA RYZHIK Abstract. We consider systems of reactive Boussinesq equations in two
More informationThe small ball property in Banach spaces (quantitative results)
The small ball property in Banach spaces (quantitative results) Ehrhard Behrends Abstract A metric space (M, d) is said to have the small ball property (sbp) if for every ε 0 > 0 there exists a sequence
More informationOn a Suitable Weak Solution of the Navier Stokes Equation with the Generalized Impermeability Boundary Conditions
Proceedings of the 3rd IASME/WSEAS Int. Conf. on FLUID DYNAMICS & AERODYNAMICS, Corfu, Greece, August -, 5 pp36-41 On a Suitable Weak Solution of the Navier Stokes Equation with the Generalized Impermeability
More informationEXISTENCE OF SOLUTIONS TO BURGERS EQUATIONS IN DOMAINS THAT CAN BE TRANSFORMED INTO RECTANGLES
Electronic Journal of Differential Equations, Vol. 6 6), No. 57, pp. 3. ISSN: 7-669. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu EXISTENCE OF SOLUTIONS TO BURGERS EQUATIONS IN DOMAINS
More informationON THE EXISTENCE OF THREE SOLUTIONS FOR QUASILINEAR ELLIPTIC PROBLEM. Paweł Goncerz
Opuscula Mathematica Vol. 32 No. 3 2012 http://dx.doi.org/10.7494/opmath.2012.32.3.473 ON THE EXISTENCE OF THREE SOLUTIONS FOR QUASILINEAR ELLIPTIC PROBLEM Paweł Goncerz Abstract. We consider a quasilinear
More informationMeasure and Integration: Solutions of CW2
Measure and Integration: s of CW2 Fall 206 [G. Holzegel] December 9, 206 Problem of Sheet 5 a) Left (f n ) and (g n ) be sequences of integrable functions with f n (x) f (x) and g n (x) g (x) for almost
More informationChapter 1 Foundations of Elliptic Boundary Value Problems 1.1 Euler equations of variational problems
Chapter 1 Foundations of Elliptic Boundary Value Problems 1.1 Euler equations of variational problems Elliptic boundary value problems often occur as the Euler equations of variational problems the latter
More informationSecond Order Elliptic PDE
Second Order Elliptic PDE T. Muthukumar tmk@iitk.ac.in December 16, 2014 Contents 1 A Quick Introduction to PDE 1 2 Classification of Second Order PDE 3 3 Linear Second Order Elliptic Operators 4 4 Periodic
More informationOn the p-laplacian and p-fluids
LMU Munich, Germany Lars Diening On the p-laplacian and p-fluids Lars Diening On the p-laplacian and p-fluids 1/50 p-laplacian Part I p-laplace and basic properties Lars Diening On the p-laplacian and
More informationLecture No 2 Degenerate Diffusion Free boundary problems
Lecture No 2 Degenerate Diffusion Free boundary problems Columbia University IAS summer program June, 2009 Outline We will discuss non-linear parabolic equations of slow diffusion. Our model is the porous
More informationMath The Laplacian. 1 Green s Identities, Fundamental Solution
Math. 209 The Laplacian Green s Identities, Fundamental Solution Let be a bounded open set in R n, n 2, with smooth boundary. The fact that the boundary is smooth means that at each point x the external
More information(convex combination!). Use convexity of f and multiply by the common denominator to get. Interchanging the role of x and y, we obtain that f is ( 2M ε
1. Continuity of convex functions in normed spaces In this chapter, we consider continuity properties of real-valued convex functions defined on open convex sets in normed spaces. Recall that every infinitedimensional
More information