HOW TO APPROXIMATE THE HEAT EQUATION WITH NEUMANN BOUNDARY CONDITIONS BY NONLOCAL DIFFUSION PROBLEMS. 1. Introduction
|
|
- Beverley Camilla Hoover
- 5 years ago
- Views:
Transcription
1 HOW TO APPROXIMATE THE HEAT EQUATION WITH NEUMANN BOUNDARY CONDITIONS BY NONLOCAL DIFFUSION PROBLEMS CARMEN CORTAZAR, MANUEL ELGUETA, ULIO D. ROSSI, AND NOEMI WOLANSKI Abstract. We present a model for nonlocal diffusion with Neumann boundary conditions in a bounded smooth domain prescribing the flux through the boundary. We stu the limit of this family of nonlocal diffusion operators when a rescaling parameter related to the kernel of the nonlocal operator goes to zero. We prove that the solutions of this family of problems converge to a solution of the heat equation with Neumann boundary conditions. 1. Introduction The purpose of this article is to show that the solutions of the usual Neumann boundary value problem for the heat equation can be approximated by solutions of a sequence of nonlocal Neumann boundary value problems. Let : R N R be a nonnegative, radial, continuous function with z dz = 1. R N Assume also that is strictly positive in B, d and vanishes in R N \ B, d. Nonlocal evolution equations of the form 1.1 u t x, t = u ux, t = x yuy, t ux, t, R N and variations of it, have been recently widely used to model diffusion processes. More precisely, as stated in [1], if ux, t is thought of as a density at the point x at time t and x y is thought of as the probability distribution of jumping from location y to location x, then R N y xuy, t = ux, t is the rate at which individuals are arriving at position x from all other places and ux, t = R N y xux, t is the rate at which they are leaving location x to travel to all other sites. This consideration, in the absence of external or internal sources, leads immediately to the fact that the density u satisfies equation 1.1. For recent references on nonlocal diffusion see, [1], [2], [3], [4], [5], [6], [9], [1], [12], [13], [14] and references therein. Given a bounded, connected and smooth domain, one of the most common boundary conditions that has been imposed in the literature to the heat equation, u t = u, is the Neumann boundary condition, u/ ηx, t = gx, t, x, which leads to the following Key words and phrases. Nonlocal diffusion, boundary value problems. 2 Mathematics Subject Classification 35K57, 35B4. 1
2 2 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI classical problem, 1.2 u t u = in, T, u = g on, T, η ux, = u x in. In this article we propose a nonlocal Neumann boundary value problem, namely 1.3 u t x, t = x y uy, t ux, t + Gx, x ygy, t, R N \ where Gx, ξ is smooth and compactly supported in ξ uniformly in x. In this model the first integral takes into account the diffusion inside. In fact, as we have explained, the integral x yuy, t ux, t takes into account the individuals arriving or leaving position x from or to other places. Since we are integrating in, we are imposing that diffusion takes place only in. The last term takes into account the prescribed flux of individuals that enter or leave the domain. The nonlocal Neumann model 1.3 and the Neumann problem for the heat equation 1.2 share many properties. For example, a comparison principle holds for both equations when G is nonnegative and the asymptotic behavior of their solutions as t is similar, see [8]. Existence and uniqueness of solutions of 1.3 with general G is proved by a fixed point argument in Section 2. Also, a comparison principle when G is proved in that section. Our main goal is to show that the Neumann problem for the heat equation 1.2, can be approximated by suitable nonlocal Neumann problems 1.3. More precisely, for given and G we consider the rescaled kernels 1 ξ 1.4 ξ = C 1 1, G N x, ξ = C 1 G x, ξ N with C1 1 = 1 zzn 2 dz, 2 B,d which is a normalizing constant in order to obtain the Laplacian in the limit instead of a multiple of it. Then, we consider the solution u x, t to u tx, t = 1 2 x yu y, t u x, t G x, x ygy, t, R N \ u x, = u x. We prove in this paper that u u in different topologies according to two different choices of the kernel G.
3 NONLOCAL DIFFUSION PROBLEMS 3 Let us give an heuristic idea in one space dimension, with =, 1, of why the scaling involved in 1.4 is the correct one. We assume that 1 G1, 1 y = G, y = 1 y y and, as stated above, Gx, has compact support independent of x. In this case 1.5 reads u t x, t = x y uy, t ux, t + 1 G x, x y gy, t G x, x y gy, t := A ux, t. If x, 1 a Taylor expansion gives that for any fixed smooth u and small enough, the right hand side A u in 1.5 becomes and if x = and small, A ux = x y uy ux u xx x A u = y uy u + 1 G, y gy C 2 u x g. Analogously, A u1 C 2 / u x 1 + g1. However, the proofs of our results are much more involved than simple Taylor expansions due to the fact that for each > there are points x for which the ball in which integration takes place, Bx, d, is not contained in. Moreover, when working in several space dimensions, one has to take into account the geometry of the domain. Our first result deals with homogeneous boundary conditions, this is, g. Theorem 1.1. Assume g. Let be a bounded C 2+α domain for some < α < 1. Let u C 2+α,1+α/2 [, T ] be the solution to 1.2 and let u be the solution to 1.5 with as above. Then, as. sup u, t u, t L t [,T ] Note that this result holds for every G since g, and that the assumed regularity in u is guaranteed if u C 2+α and u / η =. See, for instance, [11]. We will prove Theorem 1.1 by constructing adequate super and subsolutions and then using comparison arguments to get bounds for the difference u u. Now we will make explicit the functions G we will deal with in the case g. To define the first one let us introduce some notation. As before, let be a bounded C 2+α domain. For x := {x distx, < d} and small enough we write
4 4 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI x = x s d η x where x is the orthogonal projection of x on, < s < and η x is the unit exterior normal to at x. Under these assumptions we define 1.6 G 1 x, ξ = ξ η x ξ for x. Notice that the last integral in 1.5 only involves points x since when y, x y supp implies that x. Hence the above definition makes sense for small. For this choice of the kernel, G = G 1, we have the following result. Theorem 1.2. Let be a bounded C 2+α domain, g C 1+α,1+α/2 R N \ [, T ], u C 2+α,1+α/2 [, T ] the solution to 1.2, for some < α < 1. Let as before and Gx, ξ = G 1 x, ξ, where G 1 is defined by 1.6. Let u be the solution to 1.5. Then, as. sup u, t u, t L 1 t [,T ] Observe that G 1 may fail to be nonnegative and hence a comparison principle may not hold. However, in this case our proof of convergence to the solution of the heat equation does not rely on comparison arguments for 1.3. If we want a nonnegative kernel G, in order to have a comparison principle, we can modify G 1 by taking instead. G 1 x, ξ = G 1 x, ξ + κ ξ = 1 ξ η x ξ + κ 2 Note that for x and y R N \, G 1 x, x y = 1 x y η x x y + κ 2 is nonnegative for small if we choose the constant κ as a bound for the curvature of, since x y d. As will be seen in Remark 4.1, Theorem 1.2 remains valid with G 1 replaced by G 1. Finally, the other Neumann kernel we propose is where C 2 is such that 1.7 d Gx, ξ = G 2 x, ξ = C 2 ξ, {z N >s} z C 2 z N dz ds =. This choice of G is natural since we are considering a flux with a jumping probability that is a scalar multiple of the same jumping probability that moves things in the interior of the domain,. Several properties of solutions to 1.3 have been recently investigated in [8] in the case G = G 2 for different choices of g. For the case of G 2 we can still prove convergence but in a weaker sense. Theorem 1.3. Let be a bounded C 2+α domain, g C 1+α,1+α/2 R N \ [, T ], u C 2+α,1+α/2 [, T ] the solution to 1.2, for some < α < 1. Let as before and
5 NONLOCAL DIFFUSION PROBLEMS 5 Gx, ξ = G 2 x, ξ = C 2 ξ, where C 2 is defined by 1.7. Let u be the solution to 1.5. Then, for each t [, T ] u x, t ux, t weakly in L as. The rest of the paper is organized as follows: in Section 2 we prove existence, uniqueness and a comparison principle for our nonlocal equation. In Section 3 we prove the uniform convergence when g =. In Section 4 we deal with the case G = G 1 and finally in Section 5 we prove our result when G = G Existence and uniqueness In this section we deal with existence and uniqueness of solutions of 1.3. Our result is valid in a general L 1 setting. Theorem 2.1. Let be a bounded domain. Let L 1 R N and G L R N. For every u L 1 and g L loc [, ; L1 R N \ there exists a unique solution u of 1.3 such that u C[, ; L 1 and ux, = u x. As in [7] and [8], existence and uniqueness will be a consequence of Banach s fixed point theorem. We follow closely the ideas of those works in our proof, so we will only outline the main arguments. Fix t > and consider the Banach space X t = C[, t ]; L 1 with the norm w = max t t w, t L 1. We will obtain the solution as a fixed point of the operator T u,g : X t X t t T u,gwx, t = u x + x y wy, s wx, s ds t R N \ Gx, x ygy, t ds. defined by The following lemma is the main ingredient in the proof of existence. Lemma 2.1. Let and G as in Theorem 2.1. Let g, h L, t ; L 1 R N \ and u, v L 1. There exists a constant C depending only on, and G such that for w, z X t, 2.2 T u,gw T v,hz u v L 1 +Ct w z + g h L,t ;L 1 R N \.
6 6 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI Proof. We have T u,gwx, t T v,hzx, t dx u x v x dx t [ ] + x y wy, s zy, s wx, s zx, s ds dx + t R N \ Gx, x y gy, s hy, s ds dx. Therefore, we obtain 2.2. Proof of Theorem 2.1. Let T = T u,g. We check first that T maps X t into X t. From 2.1 we see that for t 1 < t 2 t, t2 t2 T wt 2 T wt 1 L 1 A wy, s ds + B gy, s ds. On the other hand, again from 2.1 t 1 t 1 R N \ T wt u L 1 Ct { w + g L,t ;L 1 R N \}. These two estimates give that T w C[, t ]; L 1. Hence T maps X t into X t. Choose t such that Ct < 1. From Lemma 2.1 we get that T is a strict contraction in X t and the existence and uniqueness part of the theorem follows from Banach s fixed point theorem in the interval [, t ]. To extend the solution to [, we may take as initial datum ux, t L 1 and obtain a solution in [, 2 t ]. Iterating this procedure we get a solution defined in [,. Our next aim is to prove a comparison principle for 1.3 when, G. To this end we define what we understand by sub and supersolutions. Definition 2.1. A function u C[, T ; L 1 is a supersolution of 1.3 if ux, u x and u t x, t x y uy, t ux, t + Gx, x ygy, t. R N \ Subsolutions are defined analogously by reversing the inequalities. Lemma 2.2. Let, G, u and g. If u C [, T ] is a supersolution to 1.3, then u. Proof. Assume that ux, t is negative somewhere. Let vx, t = ux, t + t with so small such that v is still negative somewhere. Then, if we take x, t a point where v
7 NONLOCAL DIFFUSION PROBLEMS 7 attains its negative minimum, there holds that t > and v t x, t = u t x, t + > x yuy, t ux, t = x yvy, t vx, t which is a contradiction. Thus, u. Corollary 2.1. Let, G and bounded. Let u and v in L 1 with u v and g, h L, T ; L 1 R N \ with g h. Let u be a solution of 1.3 with initial condition u and flux g and v be a solution of 1.3 with initial condition v and flux h. Then, u v a.e. Proof. Let w = u v. Then, w is a supersolution with initial datum u v and boundary datum g h. Using the continuity of solutions with respect to the initial and Neumann data Lemma 2.1 and the fact that L R N, G L R N we may assume that u, v C [, T ]. By Lemma 2.2 we obtain that w = u v. So the corollary is proved. Corollary 2.2. Let, G and bounded. Let u C [, T ] resp. v be a supersolution resp. subsolution of 1.3. Then, u v. Proof. It follows the lines of the proof of the previous corollary. 3. Uniform convergence in the case g In order to prove Theorem 1.1 we set w = u u and let ũ be a C 2+α,1+α/2 extension of u to R N [, T ]. We define L v = 1 2 x y vy, t vx, t and L v = 1 2 R N x y vy, t vx, t. Or Then wt = L u u + 1 G x, x ygy, t R N \ = L w + L ũ u + 1 G x, x ygy, t R N \ 1 2 x y ũy, t ũx, t. R N \ w t L w = F x, t,
8 8 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI where, noting that u = ũ in, F x, t = L ũ ũ R N \ R N \ G x, x ygy, t x y ũy, t ũx, t. Our main task in order to prove the uniform convergence result is to get bounds on F. First, we observe that it is well known that by the choice of C 1, the fact that is radially symmetric and ũ C 2+α,1+α/2 R N [, T ], we have that 3.1 sup L ũ ũ L = O α. t [,T ] In fact, C 1 N+2 R N x y ũy, t ũx, t ũx, t becomes, under the change variables z = x y/, C 1 z ũx z, t ũx, t ũx, t 2 R N and hence 3.1 follows by a simple Taylor expansion. Next, we will estimate the last integral in F. We remark that the next lemma is valid for any smooth function, not only for a solution to the heat equation. Lemma 3.1. If θ is a C 2+α,1+α/2 function on R N [, T ] and θ = h on, then for η x = {z dist z, < d} and small, 1 2 x y θy, t θx, t = 1 y x x yη x h x, t R N \ R N \ + x y D β θ [ 2 x, t y x β x x ] β + O α, R N \ β =2 where x is the orthogonal projection of x on the boundary of so that x y 2d. Proof. Since θ C 2+α,1+α/2 R N [, T ] we have θy, t θx, t = θy, t θ x, t θx, t θ x, t = θ x, t y x + β =2 + O x x 2+α + O x y 2+α. D β θ 2 x, t[ y x β x x β]
9 Therefore, 1 2 x y θy, t θx, t = 1 R N \ + x y D β θ [ 2 x, t y x R N \ NONLOCAL DIFFUSION PROBLEMS 9 β =2 R N \ x y θ x, t β x x y x β ] + O α. Fix x. Let us take a new coordinate system such that η x = e N. Since θ η = h on, we get y x x y θ x, t R N \ = R N \ x yη x y x h x, t + R N \ x y θ xi x, t y i x i We will estimate this last integral. Since is a C 2+α domain we can chose vectors e 1, e 2,..., e so that there exists κ > and constants f i x such that { B 2d x Therefore x y R N \ = y N x N + f i xy i x i 2 > κ 2+α } R N \, { B 2d x y N x } N + f i xy i x i 2 < κ 2+α. R N \ + = I 1 + I 2. θ xi x, t y i x i yn x N + f i xy i x i 2 κ 2+α x y y N x N + x y f i xy i x i 2 >κ 2+α. θ xi x, t y i x i θ xi x, t y i x i If we take z = y x/ as a new variable, recalling that x N x N = s, we obtain I 1 C 1 θ xi x, t zn s+ f i xz i 2 κ 1+α z z i dz C κ 1+α.
10 1 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI On the other hand, I 2 = C 1 θ xi x, t z N s+ f i xz i 2 >κ 1+α z z i dz. Fix 1 i N 1. Then, since { is radially symmetric, z z i is an odd function of the variable z i and, since the set z N s + f i xz i 2 } > κ 1+α is symmetric in that variable we get I 2 =. Collecting the previous estimates the lemma is proved. We will also need the following inequality. Lemma 3.2. There exist K > and > such that, for <, y x 3.2 x yη x K x y. R N \ R N \ Proof. Let us put the origin at the point x and take a coordinate system such that η x = e N. Then, x =, µ with < µ < d. Then, arguing as before, y x x yη x = x y y N + µ = {y N >κ 2 } {y N >κ 2 } Fix c 1 small such that 1 2 x y y N + µ x y y N + µ {z N >} + C. R N \ z z N dz 2c 1 R N \ R N \ { y N <κ 2 } {<z N <2c 1 } x y y N + µ z dz. We divide our arguments into two cases according to whether µ c 1 or µ > c 1. Case I Assume µ c 1. In this case we have, x y y N + µ = C 1 z z N dz {y N >κ 2 } {z N >κ+ µ } 3.3 = C 1 z z N dz z z N dz {z N >} {<z N <κ+ µ } C 1 z z N dz 2c 1 z dz C 1 2 {z N >} {<z N <2c 1 } {z N >} z z N dz.
11 Then, R N \ C if is small enough and NONLOCAL DIFFUSION PROBLEMS 11 x yη x {z N >} y x K R N \ z z N dz K C, K < 1 4 {z N >} z z N dz. x y Case II Assume that µ c 1. For y in R N \ B x, d we have y N κ. Then, x y y N + µ K x y R N \ R N \ c 1 κ x y K x y R N \ R N \ = c 1 κ K R N \ x y, if is small and This ends the proof of 3.2. We now prove Theorem 1.1. K < c 1 2. Proof of Theorem 1.1. We will use a comparison argument. First, let us look for a supersolution. Let us pick an auxiliary function v as a solution to v t v = hx, t in, T, v η = g 1x, t on, T, vx, = v 1 x in. for some smooth functions hx, t 1, g 1 x, t 1 and v 1 x such that the resulting v has an extension ṽ that belongs to C 2+α,1+α/2 R N [, T ], and let M be an upper bound for v in [, T ]. Then, v t = L v + v L ṽ x yṽy, t ṽx, t + hx, t. R N \
12 12 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI Since v = ṽ in, we have that v is a solution to { v t L v = Hx, t, in, T, vx, = v 1 x in, where by 3.1, Lemma 3.1 and the fact that h 1, Hx, t, = ṽ L ṽ x yṽy, t ṽx, t + hx, t 1 + R N \ R N \ g1 x, t R N \ x yη x x y R N \ β =2 x yη x y x g 1 x, t D β ṽ [ 2 x, t y x y x for some constant D 1 if is small so that C α 1/2. β x x ] β + 1 C α D 1 R N \ x y Now, observe that Lemma 3.2 implies that for every constant C > there exists such that, 1 y x x yη x C x y, R N \ R N \ if <. Now, since g =, by 3.1 and Lemma 3.1 we obtain F C α + x y R N \ C α + C 2 R N \ β =2 x y. D β ũ [ 2 x, t y x Given δ >, let v δ = δv. Then v δ verifies { v δ t L v δ = δhx, t, in, T, v δ x, = δv 1 x in. β x x ] β By our previous estimates, there exists = δ such that for, F δhx, t,. So, by the comparison principle for any it holds that Therefore, for every δ >, Mδ v δ w v δ Mδ. Mδ lim inf w lim sup w Mδ.
13 NONLOCAL DIFFUSION PROBLEMS 13 and the theorem is proved. 4. Convergence in L 1 in the case G = G 1 First we prove that F goes to zero as goes to zero. Lemma 4.1. If G = G 1 then as. R N \ F x, t in L [, T ]; L 1 Proof. As G = G 1 = ξ η x ξ, for x, by 3.1 and Lemma 3.1, F x, t = 1 y x x yη x gy, t g x, t R N \ x y D β ũ [ 2 x, t y x β x x ] β + O α. β =2 As g is smooth, we have that F is bounded in. Recalling the fact that = O and F x, t = O α on \ we get the convergence result. We are now rea to prove Theorem 1.2. Proof of Theorem 1.2. In the case G = G 1 we have proven in Lemma 4.1 that F in L 1 [, T ]. On the other hand, we have that w = u u is a solution to Let z be a solution to Then z is a solution to By comparison we have that w t L w = F wx, =. z t L z = F zx, =. z t L z = F zx, =. z w z and z. Integrating the equation for z we get z, t L 1 = z x, t dx = Applying Lemma 4.1 we get as. So the theorem is proved. t sup z, t L 1 t [,T ] F x, s ds dx.
14 14 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI Remark 4.1. Notice that if we consider a kernel G which is a modification of G 1 of the form with G x, ξ = G 1 x, ξ + Ax, ξ, R N \ Ax, x y, in L 1 as, then the conclusion of Theorem 1.2 is still valid. In particular, we can take Ax, ξ, = κ ξ. 5. Weak convergence in L 1 in the case G = G 2 First, we prove that in this case F goes to zero as measures. Lemma 5.1. If G = G 2 then there exists a constant C independent of such that T F x, s dx ds C. Moreover, F x, t as measures as. That is, for any continuous function θ, it holds that T F x, tθx, t dx dt as. Proof. As G = G 2 = C 2 ξ and g and ũ are smooth, taking again the coordinate system of Lemma 3.1, we obtain F x, t = 1 x y C 2 gy, t y N x N g x, t R N \ 1 x y ũ xi x, t y i x i R N \ x y D β ũ x, t [ y x β x x ] β + O α R N \ 2 β =2 = 1 x y C 2 g x, t y N x N g x, t R N \ 1 x y ũ xi x, t y i x i + O1χ + O α. R N \
15 Let NONLOCAL DIFFUSION PROBLEMS 15 B x, t := x y C 2 g x, t y N x N R N \ R N \ x y ũ xi x, t y i x i g x, t Proceeding in a similar way as in the proof of Lemma 3.1 we get for small, x y C 2 g x, t y N x N g x, t R N \ = g x, t x y C 2 y N x N And + g x, t g x, t R N \ { y N x N κ 2 } R N \ {y N x N >} R N \ {<y N x N <κ 2 }. x y C 2 y N x N = C 1 g x, t zc 2 z N dz + Oχ. {z N >s} = R N \ + x y ũ xi x, t y i x i ũ xi x, t ũ xi x, t = C 1 ũ xi x, t = I 2 + Oχ. { y N x N κ 2 } {y N x N >κ 2 } {z N s>κ} x y C 2 y N x N x y y i x i x y y i x i zz i dz + Oχ As in Lemma 3.1 we have I 2 =. Therefore, B x, t = C 1 g x, t z C 2 z N dz + Oχ. {z N >s} Now, we observe that B is bounded and supported in. Hence t F x, τ dx dτ 1 t B x, τ dx dτ + Ct + Ct α C. This proves the first assertion of the lemma.
16 16 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI Now, let us write for a point x x = x µη x with < µ < d. For small and < µ < d, let ds µ be the area element of {x dist x, = µ}. Then, ds µ = ds + O, where ds is the area element of. So that, taking now µ = s we get for any continuous test function θ, 1 T B x, tθ x, t dx dt T d = O + C 1 g x, tθ x, t z C 2 z N dz ds ds dt = O as, since we have chosen C 2 so that d {z N >s} {z N >s} z C 2 z N dz ds =. Now, with all these estimates, we go back to F. We have F x, t = 1 B x, t + O1χ + O α. Thus, we obtain T F x, tθ x, t dx dt as. Now, if σr is the modulus of continuity of θ, T T F x, tθx, t dx dt = F x, tθ x, t dx dt T + F x, t θx, t θ x, t dx dt T T F x, tθ x, t dx dt + Cσ F x, t dx dt as. Finally, the observation that F = O α in \ gives T and this ends the proof. \ F x, tθx, t dx dt as Now we prove that u is uniformly bounded when G = G 2. Lemma 5.2. Let G = G 2. There exists a constant C independent of such that u L [,T ] C.
17 NONLOCAL DIFFUSION PROBLEMS 17 Proof. Again we will use a comparison argument. Let us look for a supersolution. Pick an auxiliary function v as a solution to v t v = hx, t in, T, 5.1 v η = g 1x, t on, T, vx, = v 1 x in. for some smooth functions hx, t 1, v 1 x u x and g 1 x, t 2 K C max gx, t + 1 K as in 3.2 [,T ] such that the resulting v has an extension ṽ that belongs to C 2+α,1+α/2 R N [, T ] and let M be an upper bound for v in [, T ]. As before v is a solution to { v t L v = Hx, t, in, T, vx, = v 1 x in, where H verifies g1 x, t Hx, t, So that, by Lemma 3.2, for <. R N \ x yη x Hx, t, g 1 x, t K Let us recall that F x, t = L ũ ũ + C y x D 1 R N \ D 1 x y + 1 R N \ 2 R N \ R N \ x ygy, t Then, proceeding once again as in Lemma 3.1 we have, F x, t g x, t C 2 g x, t x y + R N \ + C α + C x y R N \ [ C2 + 1 ] max gx, t + C [,T ] g 1 x, t K 2 if <, by our choice of g 1. x y ũy, t ũx, t. R N \ + C x y + C α R N \ R N \ x y + C α x y x y y x η x
18 18 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI Therefore, for every small enough, we obtain F x, t Hx, t,, and, by a comparison argument, we conclude that M vx, t u x, t vx, t M, for every x, t [, T ]. This ends the proof. Finally, we prove our last result, Theorem 1.3. Proof of Theorem 1.3. By Lemma 5.1 we have that as. F x, t as measures in [, T ] Assume first that ψ C 2+α and let ϕ be the solution to w t L w = wx, = ψx. Let ϕ be a solution to ϕ t ϕ = ϕ η = ϕx, = ψx. Then, by Theorem 1.1 we know that ϕ ϕ uniformly in [, T ]. For a fixed t > set ϕ x, s = ϕ x, t s. Then ϕ satisfies ϕ s + L ϕ =, for s < t, ϕx, t = ψx. Analogously, set ϕx, s = ϕx, t s. Then ϕ satisfies ϕ t + ϕ = ϕ η = ϕx, t = ψx.
19 NONLOCAL DIFFUSION PROBLEMS 19 Then, for w = u u we have t w w t x, t ψx dx = s x, s ϕ ϕ x, s dx ds + s x, s w x, s dx ds t t = L w x, sϕ x, s dx ds + F x, s ϕ x, s dx ds t ϕ + s x, s w x, s dx ds t t = L ϕ x, sw x, s dx ds + F x, s ϕ x, s dx ds t ϕ + s x, s w x, s dx ds t = F x, sϕ x, s dx ds. Now we observe that, by the Lemma 5.1, t t F x, sϕ x, s dx ds + sup ϕ x, s ϕx, s L <s<t F x, sϕx, s dx ds t F x, s dx ds as. This proves the result when ψ C 2+α. Now we deal with the general case. Let ψ L 1. Choose ψ n C 2+α such that ψ n ψ in L 1. We have w x, t ψx dx w x, t ψ n x dx + ψ n ψ L 1 w L. By Lemma 5.2, {w } is uniformly bounded, and hence the result follows. Acknowledgements. Supported by Universidad de Buenos Aires under grants X52 and X66, by ANPCyT PICT No , Fundacion Antorchas Project 139-5, by CONICET Argentina and by FONDECYT Project and Coop. Int Chile. References [1] P. Bates and A. Chmaj. An integrodifferential model for phase transitions: stationary solutions in higher dimensions.. Statistical Phys., 95, , [2] P. Bates and A. Chmaj. A discrete convolution model for phase transitions. Arch. Rat. Mech. Anal., 15, , [3] P. Bates, P. Fife, X. Ren and X. Wang. Travelling waves in a convolution model for phase transitions. Arch. Rat. Mech. Anal., 138, , 1997.
20 2 C. CORTAZAR, M. ELGUETA,.D. ROSSI, AND N. WOLANSKI [4] P. Bates and. Han. The Dirichlet boundary problem for a nonlocal Cahn-Hilliard equation. To appear in. Math. Anal. Appl. [5] P. Bates and. Han. The Neumann boundary problem for a nonlocal Cahn-Hilliard equation.. Differential Equations, 212, , 25. [6] C. Carrillo and P. Fife. Spatial effects in discrete generation population models.. Math. Biol. 52, , 25. [7] C. Cortazar, M. Elgueta and. D. Rossi. A non-local diffusion equation whose solutions develop a free boundary. Ann. Henri Poincare, 62, , 25. [8] C. Cortazar, M. Elgueta,. D. Rossi and N. Wolanski. Boundary fluxes for non-local diffusion. Preprint. [9] X Chen. Existence, uniqueness and asymptotic stability of travelling waves in nonlocal evolution equations. Adv. Differential Equations, 2, , [1] P. Fife. Some nonclassical trends in parabolic and parabolic-like evolutions. Trends in nonlinear analysis, , Springer, Berlin, 23. [11] A. Friedman. Partial Differential Equations of Parabolic Type. Prentice-Hall, Englewood Cliffs, N, [12] C. Lederman and N. Wolanski. Singular perturbation in a nonlocal diffusion problem. To appear in Comm. Partial Differential Equations. [13] X. Wang. Metaestability and stability of patterns in a convolution model for phase transitions.. Differential Equations, 183, , 22. [14] L. Zhang. Existence, uniqueness and exponential stability of traveling wave solutions of some integral differential equations arising from neuronal networks.. Differential Equations 1971, , 24. Carmen Cortazar and Manuel Elgueta Departamento de Matemática, Universidad Catolica de Chile, Casilla 36, Correo 22, Santiago, Chile. address: ccortaza@mat.puc.cl, melgueta@mat.puc.cl. ulio D. Rossi Consejo Superior de Investigaciones Científicas CSIC, Serrano 123, Madrid, Spain, on leave from Departamento de Matemática, FCEyN UBA 1428 Buenos Aires, Argentina. address: jrossi@dm.uba.ar Noemi Wolanski Departamento de Matemática, FCEyN UBA 1428 Buenos Aires, Argentina. address: wolanski@dm.uba.ar
BOUNDARY FLUXES FOR NON-LOCAL DIFFUSION
BOUNDARY FLUXES FOR NON-LOCAL DIFFUSION CARMEN CORTAZAR, MANUEL ELGUETA, JULIO D. ROSSI, AND NOEMI WOLANSKI Abstract. We study a nonlocal diffusion operator in a bounded smooth domain prescribing the flux
More informationNONLOCAL DIFFUSION EQUATIONS
NONLOCAL DIFFUSION EQUATIONS JULIO D. ROSSI (ALICANTE, SPAIN AND BUENOS AIRES, ARGENTINA) jrossi@dm.uba.ar http://mate.dm.uba.ar/ jrossi 2011 Non-local diffusion. The function J. Let J : R N R, nonnegative,
More informationBlow-up for a Nonlocal Nonlinear Diffusion Equation with Source
Revista Colombiana de Matemáticas Volumen 46(2121, páginas 1-13 Blow-up for a Nonlocal Nonlinear Diffusion Equation with Source Explosión para una ecuación no lineal de difusión no local con fuente Mauricio
More informationTHE NEUMANN PROBLEM FOR THE -LAPLACIAN AND THE MONGE-KANTOROVICH MASS TRANSFER PROBLEM
THE NEUMANN PROBLEM FOR THE -LAPLACIAN AND THE MONGE-KANTOROVICH MASS TRANSFER PROBLEM J. GARCÍA-AZORERO, J. J. MANFREDI, I. PERAL AND J. D. ROSSI Abstract. We consider the natural Neumann boundary condition
More informationAsymptotics for evolution problems with nonlocal diffusion. Julio D. Rossi
Asymptotics for evolution problems with nonlocal diffusion Julio D. Rossi IMDEA Matemáticas, C-IX, Campus Cantoblanco, UAM, Madrid, Spain and Departamento de Matemática, FCEyN UBA (1428) Buenos Aires,
More informationTHE CAUCHY PROBLEM AND STEADY STATE SOLUTIONS FOR A NONLOCAL CAHN-HILLIARD EQUATION
Electronic Journal of Differential Equations, Vol. 24(24), No. 113, pp. 1 9. ISSN: 172-6691. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu ftp ejde.math.txstate.edu (login: ftp) THE CAUCHY
More informationSimultaneous vs. non simultaneous blow-up
Simultaneous vs. non simultaneous blow-up Juan Pablo Pinasco and Julio D. Rossi Departamento de Matemática, F.C.E y N., UBA (428) Buenos Aires, Argentina. Abstract In this paper we study the possibility
More informationEQUAZIONI A DERIVATE PARZIALI. STEKLOV EIGENVALUES FOR THE -LAPLACIAN
EQUAZIONI A DERIVATE PARZIALI. STEKLOV EIGENVALUES FOR THE -LAPLACIAN J. GARCIA-AZORERO, J. J. MANFREDI, I. PERAL AND J. D. ROSSI Abstract. We study the Steklov eigenvalue problem for the - laplacian.
More informationLaplace s Equation. Chapter Mean Value Formulas
Chapter 1 Laplace s Equation Let be an open set in R n. A function u C 2 () is called harmonic in if it satisfies Laplace s equation n (1.1) u := D ii u = 0 in. i=1 A function u C 2 () is called subharmonic
More informationAN ESTIMATE FOR THE BLOW-UP TIME IN TERMS OF THE INITIAL DATA
AN ESTIMATE FOR THE BLOW-UP TIME IN TERMS OF THE INITIAL DATA JULIO D. ROSSI Abstract. We find an estimate for the blow-up time in terms of the initial data for solutions of the equation u t = (u m ) +
More informationSimultaneous vs. non simultaneous blow-up
Simultaneous vs. non simultaneous blow-up Juan Pablo Pinasco and Julio D. Rossi Departamento de Matemática, F..E y N., UBA (428) Buenos Aires, Argentina. Abstract In this paper we study the possibility
More informationMULTIPLE SOLUTIONS FOR THE p-laplace EQUATION WITH NONLINEAR BOUNDARY CONDITIONS
Electronic Journal of Differential Equations, Vol. 2006(2006), No. 37, pp. 1 7. ISSN: 1072-6691. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu ftp ejde.math.txstate.edu (login: ftp) MULTIPLE
More informationASYMPTOTIC BEHAVIOR FOR NONLOCAL DIFFUSION EQUATIONS
ASYMPTOTIC BEHAVIOR FOR NONLOCAL DIFFUSION EQUATIONS EMMANUEL CHASSEIGNE, MANUELA CHAVES AND JULIO D. ROSSI Abstract. We study the asymptotic behavior for nonlocal diffusion models of the form u t = J
More informationAN ASYMPTOTIC MEAN VALUE CHARACTERIZATION FOR p-harmonic FUNCTIONS. To the memory of our friend and colleague Fuensanta Andreu
AN ASYMPTOTIC MEAN VALUE CHARACTERIZATION FOR p-harmonic FUNCTIONS JUAN J. MANFREDI, MIKKO PARVIAINEN, AND JULIO D. ROSSI Abstract. We characterize p-harmonic functions in terms of an asymptotic mean value
More informationGreen s Functions and Distributions
CHAPTER 9 Green s Functions and Distributions 9.1. Boundary Value Problems We would like to study, and solve if possible, boundary value problems such as the following: (1.1) u = f in U u = g on U, where
More informationAN ASYMPTOTIC MEAN VALUE CHARACTERIZATION FOR p-harmonic FUNCTIONS
AN ASYMPTOTIC MEAN VALUE CHARACTERIZATION FOR p-harmonic FUNCTIONS JUAN J. MANFREDI, MIKKO PARVIAINEN, AND JULIO D. ROSSI Abstract. We characterize p-harmonic functions in terms of an asymptotic mean value
More informationNON-EXTINCTION OF SOLUTIONS TO A FAST DIFFUSION SYSTEM WITH NONLOCAL SOURCES
Electronic Journal of Differential Equations, Vol. 2016 (2016, No. 45, pp. 1 5. ISSN: 1072-6691. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu ftp ejde.math.txstate.edu NON-EXTINCTION OF
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 informationEXISTENCE, UNIQUENESS AND QUENCHING OF THE SOLUTION FOR A NONLOCAL DEGENERATE SEMILINEAR PARABOLIC PROBLEM
Dynamic Systems and Applications 6 (7) 55-559 EXISTENCE, UNIQUENESS AND QUENCHING OF THE SOLUTION FOR A NONLOCAL DEGENERATE SEMILINEAR PARABOLIC PROBLEM C. Y. CHAN AND H. T. LIU Department of Mathematics,
More informationPDEs, Homework #3 Solutions. 1. Use Hölder s inequality to show that the solution of the heat equation
PDEs, Homework #3 Solutions. Use Hölder s inequality to show that the solution of the heat equation u t = ku xx, u(x, = φ(x (HE goes to zero as t, if φ is continuous and bounded with φ L p for some p.
More informationarxiv: v1 [math.ap] 25 Jul 2012
THE DIRICHLET PROBLEM FOR THE FRACTIONAL LAPLACIAN: REGULARITY UP TO THE BOUNDARY XAVIER ROS-OTON AND JOAQUIM SERRA arxiv:1207.5985v1 [math.ap] 25 Jul 2012 Abstract. We study the regularity up to the boundary
More informationRegularity of the obstacle problem for a fractional power of the laplace operator
Regularity of the obstacle problem for a fractional power of the laplace operator Luis E. Silvestre February 24, 2005 Abstract Given a function ϕ and s (0, 1), we will stu the solutions of the following
More informationREACTION-DIFFUSION EQUATIONS FOR POPULATION DYNAMICS WITH FORCED SPEED II - CYLINDRICAL-TYPE DOMAINS. Henri Berestycki and Luca Rossi
Manuscript submitted to Website: http://aimsciences.org AIMS Journals Volume 00, Number 0, Xxxx XXXX pp. 000 000 REACTION-DIFFUSION EQUATIONS FOR POPULATION DYNAMICS WITH FORCED SPEED II - CYLINDRICAL-TYPE
More informationHomogenization and error estimates of free boundary velocities in periodic media
Homogenization and error estimates of free boundary velocities in periodic media Inwon C. Kim October 7, 2011 Abstract In this note I describe a recent result ([14]-[15]) on homogenization and error estimates
More informationCRITICAL EXPONENTS FOR A SEMILINEAR PARABOLIC EQUATION WITH VARIABLE REACTION.
CRITICAL EXPONENTS FOR A SEMILINEAR PARAOLIC EQUATION WITH VARIALE REACTION. R. FERREIRA, A. DE PALO, M. PÉREZ-LLANOS AND J. D. ROSSI Abstract. In this paper we study the blow-up phenomenon for nonnegative
More informationSYMMETRY RESULTS FOR PERTURBED PROBLEMS AND RELATED QUESTIONS. Massimo Grosi Filomena Pacella S. L. Yadava. 1. Introduction
Topological Methods in Nonlinear Analysis Journal of the Juliusz Schauder Center Volume 21, 2003, 211 226 SYMMETRY RESULTS FOR PERTURBED PROBLEMS AND RELATED QUESTIONS Massimo Grosi Filomena Pacella S.
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 informationRobustness for a Liouville type theorem in exterior domains
Robustness for a Liouville type theorem in exterior domains Juliette Bouhours 1 arxiv:1207.0329v3 [math.ap] 24 Oct 2014 1 UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris,
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 information2. Function spaces and approximation
2.1 2. Function spaces and approximation 2.1. The space of test functions. Notation and prerequisites are collected in Appendix A. Let Ω be an open subset of R n. The space C0 (Ω), consisting of the C
More informationLecture No 1 Introduction to Diffusion equations The heat equat
Lecture No 1 Introduction to Diffusion equations The heat equation Columbia University IAS summer program June, 2009 Outline of the lectures We will discuss some basic models of diffusion equations and
More informationMINIMAL GRAPHS PART I: EXISTENCE OF LIPSCHITZ WEAK SOLUTIONS TO THE DIRICHLET PROBLEM WITH C 2 BOUNDARY DATA
MINIMAL GRAPHS PART I: EXISTENCE OF LIPSCHITZ WEAK SOLUTIONS TO THE DIRICHLET PROBLEM WITH C 2 BOUNDARY DATA SPENCER HUGHES In these notes we prove that for any given smooth function on the boundary of
More informationAsymptotic behavior of infinity harmonic functions near an isolated singularity
Asymptotic behavior of infinity harmonic functions near an isolated singularity Ovidiu Savin, Changyou Wang, Yifeng Yu Abstract In this paper, we prove if n 2 x 0 is an isolated singularity of a nonegative
More informationFree boundaries in fractional filtration equations
Free boundaries in fractional filtration equations Fernando Quirós Universidad Autónoma de Madrid Joint work with Arturo de Pablo, Ana Rodríguez and Juan Luis Vázquez International Conference on Free Boundary
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 informationThreshold behavior and non-quasiconvergent solutions with localized initial data for bistable reaction-diffusion equations
Threshold behavior and non-quasiconvergent solutions with localized initial data for bistable reaction-diffusion equations P. Poláčik School of Mathematics, University of Minnesota Minneapolis, MN 55455
More informationObstacle Problems Involving The Fractional Laplacian
Obstacle Problems Involving The Fractional Laplacian Donatella Danielli and Sandro Salsa January 27, 2017 1 Introduction Obstacle problems involving a fractional power of the Laplace operator appear in
More informationEXISTENCE OF SOLUTIONS TO ASYMPTOTICALLY PERIODIC SCHRÖDINGER EQUATIONS
Electronic Journal of Differential Equations, Vol. 017 (017), No. 15, pp. 1 7. ISSN: 107-6691. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu EXISTENCE OF SOLUTIONS TO ASYMPTOTICALLY PERIODIC
More informationDownloaded 01/28/15 to Redistribution subject to SIAM license or copyright; see
SIAM J. NUMER. ANAL. Vol. 49, No. 5, pp. 2103 2123 c 2011 Society for Industrial and Applied Mathematics NUMERICAL APPROXIMATIONS FOR A NONLOCAL EVOLUTION EQUATION MAYTE PÉREZ-LLANOS AND JULIO D. ROSSI
More informationParameter Dependent Quasi-Linear Parabolic Equations
CADERNOS DE MATEMÁTICA 4, 39 33 October (23) ARTIGO NÚMERO SMA#79 Parameter Dependent Quasi-Linear Parabolic Equations Cláudia Buttarello Gentile Departamento de Matemática, Universidade Federal de São
More informationCONVERGENCE OF EXTERIOR SOLUTIONS TO RADIAL CAUCHY SOLUTIONS FOR 2 t U c 2 U = 0
Electronic Journal of Differential Equations, Vol. 206 (206), No. 266, pp. 6. ISSN: 072-669. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu CONVERGENCE OF EXTERIOR SOLUTIONS TO RADIAL CAUCHY
More informationPREPUBLICACIONES DEL DEPARTAMENTO DE MATEMÁTICA APLICADA UNIVERSIDAD COMPLUTENSE DE MADRID MA-UCM
PREPUBLICACIONES DEL DEPARTAMENTO DE MATEMÁTICA APLICADA UNIVERSIDAD COMPLUTENSE DE MADRID MA-UCM 2009-13 Extremal equilibria for monotone semigroups in ordered spaces with application to evolutionary
More informationSIMULTANEOUS AND NON-SIMULTANEOUS BLOW-UP AND UNIFORM BLOW-UP PROFILES FOR REACTION-DIFFUSION SYSTEM
Electronic Journal of Differential Euations, Vol. 22 (22), No. 26, pp. 9. ISSN: 72-669. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu ftp ejde.math.txstate.edu SIMULTANEOUS AND NON-SIMULTANEOUS
More informationA CONVEX-CONCAVE ELLIPTIC PROBLEM WITH A PARAMETER ON THE BOUNDARY CONDITION
A CONVEX-CONCAVE ELLIPTIC PROBLEM WITH A PARAMETER ON THE BOUNDARY CONDITION JORGE GARCÍA-MELIÁN, JULIO D. ROSSI AND JOSÉ C. SABINA DE LIS Abstract. In this paper we study existence and multiplicity of
More informationIntegro-differential equations: Regularity theory and Pohozaev identities
Integro-differential equations: Regularity theory and Pohozaev identities Xavier Ros Oton Departament Matemàtica Aplicada I, Universitat Politècnica de Catalunya PhD Thesis Advisor: Xavier Cabré Xavier
More informationTechnische Universität Graz
Technische Universität Graz Stability of the Laplace single layer boundary integral operator in Sobolev spaces O. Steinbach Berichte aus dem Institut für Numerische Mathematik Bericht 2016/2 Technische
More informationResearch Article On the Blow-Up Set for Non-Newtonian Equation with a Nonlinear Boundary Condition
Hindawi Publishing Corporation Abstract and Applied Analysis Volume 21, Article ID 68572, 12 pages doi:1.1155/21/68572 Research Article On the Blow-Up Set for Non-Newtonian Equation with a Nonlinear Boundary
More informationFree energy estimates for the two-dimensional Keller-Segel model
Free energy estimates for the two-dimensional Keller-Segel model dolbeaul@ceremade.dauphine.fr CEREMADE CNRS & Université Paris-Dauphine in collaboration with A. Blanchet (CERMICS, ENPC & Ceremade) & B.
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 informationBLOW-UP FOR PARABOLIC AND HYPERBOLIC PROBLEMS WITH VARIABLE EXPONENTS. 1. Introduction In this paper we will study the following parabolic problem
BLOW-UP FOR PARABOLIC AND HYPERBOLIC PROBLEMS WITH VARIABLE EXPONENTS JUAN PABLO PINASCO Abstract. In this paper we study the blow up problem for positive solutions of parabolic and hyperbolic problems
More informationA note on W 1,p estimates for quasilinear parabolic equations
200-Luminy conference on Quasilinear Elliptic and Parabolic Equations and Systems, Electronic Journal of Differential Equations, Conference 08, 2002, pp 2 3. http://ejde.math.swt.edu or http://ejde.math.unt.edu
More informationOn some weighted fractional porous media equations
On some weighted fractional porous media equations Gabriele Grillo Politecnico di Milano September 16 th, 2015 Anacapri Joint works with M. Muratori and F. Punzo Gabriele Grillo Weighted Fractional PME
More informationTwo-phase heat conductors with a stationary isothermic surface
Rend. Istit. Mat. Univ. Trieste Volume 48 (206), 67 87 DOI: 0.337/2464-8728/355 Two-phase heat conductors with a stationary isothermic surface Shigeru Sakaguchi Dedicated to Professor Giovanni Alessandrini
More informationSome asymptotic properties of solutions for Burgers equation in L p (R)
ARMA manuscript No. (will be inserted by the editor) Some asymptotic properties of solutions for Burgers equation in L p (R) PAULO R. ZINGANO Abstract We discuss time asymptotic properties of solutions
More informationHARDY INEQUALITIES WITH BOUNDARY TERMS. x 2 dx u 2 dx. (1.2) u 2 = u 2 dx.
Electronic Journal of Differential Equations, Vol. 003(003), No. 3, pp. 1 8. ISSN: 107-6691. UL: http://ejde.math.swt.edu or http://ejde.math.unt.edu ftp ejde.math.swt.edu (login: ftp) HADY INEQUALITIES
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 informationSobolev Spaces. Chapter 10
Chapter 1 Sobolev Spaces We now define spaces H 1,p (R n ), known as Sobolev spaces. For u to belong to H 1,p (R n ), we require that u L p (R n ) and that u have weak derivatives of first order in L p
More informationPerron method for the Dirichlet problem.
Introduzione alle equazioni alle derivate parziali, Laurea Magistrale in Matematica Perron method for the Dirichlet problem. We approach the question of existence of solution u C (Ω) C(Ω) of the Dirichlet
More informationAuthor(s) Huang, Feimin; Matsumura, Akitaka; Citation Osaka Journal of Mathematics. 41(1)
Title On the stability of contact Navier-Stokes equations with discont free b Authors Huang, Feimin; Matsumura, Akitaka; Citation Osaka Journal of Mathematics. 4 Issue 4-3 Date Text Version publisher URL
More informationRegularity estimates for fully non linear elliptic equations which are asymptotically convex
Regularity estimates for fully non linear elliptic equations which are asymptotically convex Luis Silvestre and Eduardo V. Teixeira Abstract In this paper we deliver improved C 1,α regularity estimates
More informationProceedings of the 5th International Conference on Inverse Problems in Engineering: Theory and Practice, Cambridge, UK, 11-15th July 2005
Proceedings of the 5th International Conference on Inverse Problems in Engineering: Theory and Practice, Cambridge, UK, 11-15th July 2005 SOME INVERSE SCATTERING PROBLEMS FOR TWO-DIMENSIONAL SCHRÖDINGER
More informationNon-degeneracy of perturbed solutions of semilinear partial differential equations
Non-degeneracy of perturbed solutions of semilinear partial differential equations Robert Magnus, Olivier Moschetta Abstract The equation u + FV εx, u = 0 is considered in R n. For small ε > 0 it is shown
More informationRecent developments in elliptic partial differential equations of Monge Ampère type
Recent developments in elliptic partial differential equations of Monge Ampère type Neil S. Trudinger Abstract. In conjunction with applications to optimal transportation and conformal geometry, there
More informationWELL-POSEDNESS OF WEAK SOLUTIONS TO ELECTRORHEOLOGICAL FLUID EQUATIONS WITH DEGENERACY ON THE BOUNDARY
Electronic Journal of Differential Equations, Vol. 2017 (2017), No. 13, pp. 1 15. ISSN: 1072-6691. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu WELL-POSEDNESS OF WEAK SOLUTIONS TO ELECTRORHEOLOGICAL
More informationTRACES FOR FRACTIONAL SOBOLEV SPACES WITH VARIABLE EXPONENTS
Adv. Oper. Theory 2 (2017), no. 4, 435 446 http://doi.org/10.22034/aot.1704-1152 ISSN: 2538-225X (electronic) http://aot-math.org TRACES FOR FRACTIONAL SOBOLEV SPACES WITH VARIABLE EXPONENTS LEANDRO M.
More informationREMARKS ON THE VANISHING OBSTACLE LIMIT FOR A 3D VISCOUS INCOMPRESSIBLE FLUID
REMARKS ON THE VANISHING OBSTACLE LIMIT FOR A 3D VISCOUS INCOMPRESSIBLE FLUID DRAGOŞ IFTIMIE AND JAMES P. KELLIHER Abstract. In [Math. Ann. 336 (2006), 449-489] the authors consider the two dimensional
More informationOn a Fractional Monge Ampère Operator
Ann. PDE (015) 1:4 DOI 10.1007/s40818-015-0005-x On a Fractional Monge Ampère Operator Luis Caffarelli 1 Fernando Charro Received: 16 November 015 / Accepted: 19 November 015 / Published online: 18 December
More informationHOMEOMORPHISMS OF BOUNDED VARIATION
HOMEOMORPHISMS OF BOUNDED VARIATION STANISLAV HENCL, PEKKA KOSKELA AND JANI ONNINEN Abstract. We show that the inverse of a planar homeomorphism of bounded variation is also of bounded variation. In higher
More informationIn this chapter we study elliptical PDEs. That is, PDEs of the form. 2 u = lots,
Chapter 8 Elliptic PDEs In this chapter we study elliptical PDEs. That is, PDEs of the form 2 u = lots, where lots means lower-order terms (u x, u y,..., u, f). Here are some ways to think about the physical
More informationSobolev Spaces. Chapter Hölder spaces
Chapter 2 Sobolev Spaces Sobolev spaces turn out often to be the proper setting in which to apply ideas of functional analysis to get information concerning partial differential equations. Here, we collect
More informationarxiv: v1 [math.ap] 10 Apr 2013
QUASI-STATIC EVOLUTION AND CONGESTED CROWD TRANSPORT DAMON ALEXANDER, INWON KIM, AND YAO YAO arxiv:1304.3072v1 [math.ap] 10 Apr 2013 Abstract. We consider the relationship between Hele-Shaw evolution with
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 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 informationNon-degeneracy of perturbed solutions of semilinear partial differential equations
Non-degeneracy of perturbed solutions of semilinear partial differential equations Robert Magnus, Olivier Moschetta Abstract The equation u + F(V (εx, u = 0 is considered in R n. For small ε > 0 it is
More informationHARNACK S INEQUALITY FOR GENERAL SOLUTIONS WITH NONSTANDARD GROWTH
Annales Academiæ Scientiarum Fennicæ Mathematica Volumen 37, 2012, 571 577 HARNACK S INEQUALITY FOR GENERAL SOLUTIONS WITH NONSTANDARD GROWTH Olli Toivanen University of Eastern Finland, Department of
More informationBLOWUP THEORY FOR THE CRITICAL NONLINEAR SCHRÖDINGER EQUATIONS REVISITED
BLOWUP THEORY FOR THE CRITICAL NONLINEAR SCHRÖDINGER EQUATIONS REVISITED TAOUFIK HMIDI AND SAHBI KERAANI Abstract. In this note we prove a refined version of compactness lemma adapted to the blowup analysis
More informationBlow-up with logarithmic nonlinearities
Blow-up with logarithmic nonlinearities Raúl Ferreira, Arturo de Pablo and Julio D. Rossi January 15, 2007 Abstract We study the asymptotic behaviour of nonnegative solutions of the nonlinear diffusion
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 informationSUPER-QUADRATIC CONDITIONS FOR PERIODIC ELLIPTIC SYSTEM ON R N
Electronic Journal of Differential Equations, Vol. 015 015), No. 17, pp. 1 11. ISSN: 107-6691. URL: http://ejde.math.txstate.edu or http://ejde.math.unt.edu ftp ejde.math.txstate.edu SUPER-QUADRATIC CONDITIONS
More informationMEAN CURVATURE FLOW OF ENTIRE GRAPHS EVOLVING AWAY FROM THE HEAT FLOW
MEAN CURVATURE FLOW OF ENTIRE GRAPHS EVOLVING AWAY FROM THE HEAT FLOW GREGORY DRUGAN AND XUAN HIEN NGUYEN Abstract. We present two initial graphs over the entire R n, n 2 for which the mean curvature flow
More informationA Perron-type theorem on the principal eigenvalue of nonsymmetric elliptic operators
A Perron-type theorem on the principal eigenvalue of nonsymmetric elliptic operators Lei Ni And I cherish more than anything else the Analogies, my most trustworthy masters. They know all the secrets of
More informationEquilibria with a nontrivial nodal set and the dynamics of parabolic equations on symmetric domains
Equilibria with a nontrivial nodal set and the dynamics of parabolic equations on symmetric domains J. Földes Department of Mathematics, Univerité Libre de Bruxelles 1050 Brussels, Belgium P. Poláčik School
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 informationON THE DEFINITION AND PROPERTIES OF p-harmonious FUNCTIONS
ON THE DEFINITION AND PROPERTIES OF p-harmonious FUNCTIONS J. J. MANFREDI, M. PARVIAINEN, AND J. D. ROSSI Abstract. We consider functions that satisfy the identity } u ε(x) = α sup u ε + inf u ε + β u
More informationMATH 425, FINAL EXAM SOLUTIONS
MATH 425, FINAL EXAM SOLUTIONS Each exercise is worth 50 points. Exercise. a The operator L is defined on smooth functions of (x, y by: Is the operator L linear? Prove your answer. L (u := arctan(xy u
More informationSmall energy regularity for a fractional Ginzburg-Landau system
Small energy regularity for a fractional Ginzburg-Landau system Yannick Sire University Aix-Marseille Work in progress with Vincent Millot (Univ. Paris 7) The fractional Ginzburg-Landau system We are interest
More informationFRACTIONAL SOBOLEV SPACES WITH VARIABLE EXPONENTS AND FRACTIONAL P (X)-LAPLACIANS. 1. Introduction
FRACTIONAL SOBOLEV SPACES WITH VARIABLE EXPONENTS AND FRACTIONAL P (X-LAPLACIANS URIEL KAUFMANN, JULIO D. ROSSI AND RAUL VIDAL Abstract. In this article we extend the Sobolev spaces with variable exponents
More informationNEUMANN BOUNDARY CONDITIONS FOR THE INFINITY LAPLACIAN AND THE MONGE-KANTOROVICH MASS TRANSPORT PROBLEM
NEUMANN BOUNDARY CONDITIONS FOR THE INFINITY LAPLACIAN AND THE MONGE-KANTOROVICH MASS TRANSPORT PROBLEM J. GARCIA-AZORERO, J. J. MANFREDI, I. PERAL AND J. D. ROSSI Abstract. In this note we review some
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 informationarxiv: v3 [math.ap] 28 Feb 2017
ON VISCOSITY AND WEA SOLUTIONS FOR NON-HOMOGENEOUS P-LAPLACE EQUATIONS arxiv:1610.09216v3 [math.ap] 28 Feb 2017 Abstract. In this manuscript, we study the relation between viscosity and weak solutions
More informationSome notes on viscosity solutions
Some notes on viscosity solutions Jeff Calder October 11, 2018 1 2 Contents 1 Introduction 5 1.1 An example............................ 6 1.2 Motivation via dynamic programming............. 8 1.3 Motivation
More informationSymmetry of nonnegative solutions of elliptic equations via a result of Serrin
Symmetry of nonnegative solutions of elliptic equations via a result of Serrin P. Poláčik School of Mathematics, University of Minnesota Minneapolis, MN 55455 Abstract. We consider the Dirichlet problem
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 informationEquilibrium analysis for a mass-conserving model in presence of cavitation
Equilibrium analysis for a mass-conserving model in presence of cavitation Ionel S. Ciuperca CNRS-UMR 58 Université Lyon, MAPLY,, 696 Villeurbanne Cedex, France. e-mail: ciuperca@maply.univ-lyon.fr Mohammed
More informationNon-Constant Stable Solutions to Reaction- Diffusion Equations in Star-Shaped Domains
Rose-Hulman Undergraduate Mathematics Journal Volume 6 Issue Article 4 Non-Constant Stable Solutions to Reaction- iffusion Equations in Star-Shaped omains Greg rugan University of Texas at Austin, g_drugan@mail.utexas.edu
More informationCRITICAL EXPONENTS FOR A SEMILINEAR PARABOLIC EQUATION WITH VARIABLE REACTION.
CRITICAL EXPONENTS FOR A SEMILINEAR PARAOLIC EQUATION WITH VARIALE REACTION. RAÚL FERREIRA, ARTURO DE PALO, MAYTE PÉREZ-LLANOS, AND JULIO D. ROSSI Abstract. In this paper we study the blow-up phenomenon
More informationPresenter: Noriyoshi Fukaya
Y. Martel, F. Merle, and T.-P. Tsai, Stability and Asymptotic Stability in the Energy Space of the Sum of N Solitons for Subcritical gkdv Equations, Comm. Math. Phys. 31 (00), 347-373. Presenter: Noriyoshi
More informationFinal: Solutions Math 118A, Fall 2013
Final: Solutions Math 118A, Fall 2013 1. [20 pts] For each of the following PDEs for u(x, y), give their order and say if they are nonlinear or linear. If they are linear, say if they are homogeneous or
More informationNumerical methods for a fractional diffusion/anti-diffusion equation
Numerical methods for a fractional diffusion/anti-diffusion equation Afaf Bouharguane Institut de Mathématiques de Bordeaux (IMB), Université Bordeaux 1, France Berlin, November 2012 Afaf Bouharguane Numerical
More informationLocalization phenomena in degenerate logistic equation
Localization phenomena in degenerate logistic equation José M. Arrieta 1, Rosa Pardo 1, Anibal Rodríguez-Bernal 1,2 rpardo@mat.ucm.es 1 Universidad Complutense de Madrid, Madrid, Spain 2 Instituto de Ciencias
More information