From the N-body problem to the cubic NLS equation
|
|
- Lee Dean
- 5 years ago
- Views:
Transcription
1 From the N-body problem to the cubic NLS equation François Golse Université Paris 7 & Laboratoire J.-L. Lions golse@math.jussieu.fr Los Alamos CNLS, January 26th, 2005
2 Formal derivation by N.N. Bogolyubov (1947) see for instance Landau- Lifshitz vol. 9, 25 More recently, there have been rigorous derivations of nonlinear PDEs in the single particle phase-space from the linear, N-body problem. See for instance the derivation of the Boltzmann equation for a hard sphere gas by Lanford (1975) and then Illner-Pulvirenti (1986). Derivation of the Schrödinger-Poisson equation from the quantum N- body problem with Coulomb potential: Bardos-G-Mauser (2000), Erdös- Yau (2001) Work in collaboration with Riccardo Adami et Sandro Teta (preprint June 2005); space dimension 1, global in time. More recent preprint by L. Erdös and H.-T. Yau (preprint August 2005); space dimension 3, global in time.
3 The N-body Schrödinger equation Unknown: the N-particle wave function Ψ N Ψ N (t, X N ) C, X N = (x 1,..., x N ) R N R N Ψ N(t, X N ) 2 dx N = 1 Hamiltonian H N := 1 2 N + U N = N k= x j + 1 k<l N U(x k x l ) where the potential U(z) = U( z) is real-valued, compactly supported (hence short-range), smooth and nonnegative.
4 Hence the wave function Ψ N satisfies i t Ψ N = N k= x j Ψ N + i t Ψ N = H N Ψ N, soit 1 k<l N U(x k x l )Ψ N In the sequel, all particles considered are bosons, meaning that the wave function Ψ N is symmetrical in the variables x k (Bose statistics): Ψ N (t, x 1,..., x N ) = Ψ N (t, x σ(1),..., x σ(n) ) pour tout σ S N. One easily checks the following: if Ψ N t=0 is symmetrical in the x k s and Ψ N solves the N-body Schrödinger equation, then Ψ N (t, ) also is symmetrical in the x k s for each t R.
5 Scaling We shall be using two different scaling assumptions, as follows: a) a collective scaling of mean-field type: U(x k x l ) := 1 N V N(x k x l ) so that the interaction potential per particle is 1 2 k l b) and an ultra-short range scaling 1 N V N(x k x l ) Ψ N (X N ) 2 = O(1) V N (z) := N γ V (N γ z) with 0 < γ < 1 2, and V nonnegative, even and smooth
6 The total energy of the system of particles considered is + 1 k<l N H N Ψ N Ψ N = N k=1 1 2 x k Ψ N 2 L 2 N γ 1 V (N γ (x k x l )) Ψ N (X N ) 2 dx N We shall be using only wave functions for which H N Ψ N Ψ N = O(N) Example: an important example of such wave functions is the case of a tensor product Ψ N (X N ) := N k=1 ψ(x k ) avec ψ H 1 (R)
7 Density matrix, marginals The density matrix is the integral operator on L 2 (R N ) whose kernel is ρ N (t, X N, Y N ) := Ψ N (t, X N )Ψ N (t, Y N ) a standard notation for this operator is ρ N (t) = Ψ N (t, ) Ψ N (t, ) ; it is a rank-one orthogonal projection. For each 1 k < N, defined the k-particle marginal of ρ N to be ρ N:k (t, X k, Y k ) := R N k ρ N(t, X k, Z N k+1, Y k, Z N k+1 )dzn k+1 where Z N k+1 := (z k+1,..., z N ). We denote by ρ N:k (t) the associated integral operator; it is a nonnegative, trace-class operator with trace equal to 1.
8 Theorem. Let 0 V C (R) and γ (0, 2 1 ); assume there exists M > 0 such that t=0 N Ψ N ψ in (x k ), with ( N ) n t=0 ΨN t=0 Ψ N M n N n k=1 for n = 1,..., N. Then, for all t 0, the sequence of single-particle marginals ρ N:1 (t, x, y) ψ(t, x)ψ(t, y) as N in Hilbert-Schmidt norm, where ψ solves i t ψ xψ α ψ 2 ψ = 0, with α := ψ = ψ in t=0 R V (x)dx
9 BBGKY hierarchy We shall be writing a sequence of equations satisfied by the sequence of marginals ρ N:j, where j = 1,..., N. Start from the von Neumann equation satisfied by ρ N : i t ρ N = [H N, ρ N ] In that equation, set x 2 = y 2 = z 2,..., x N = y N = z N, and integrate in z 2,..., z N : = (N 1) i t ρ N: ( 2 x 1 2 y 1 )ρ N:1 [U(x 1 z) U(y 1 z)]ρ N:2 (t, x 1, z, y 1, z)dz We recall that U(z) = N γ 1 V (N γ z) avec 0 < γ < 1 2.
10 For j = 2,..., N 1, the analogous equation is i t ρ N:j = (N j) j k=1 + j k=1 ( 2 x k 2 y k )ρ N:j [U(x k z) U(y k z)]ρ N:j+1 (t, X k, z, Y k, z)dz 1 k<l j [U(x k x l ) U(y k y l )]ρ N:j (t, X k, Y k ) For j = N, this equation is nothing but the von Neumann equation for the N-body density matrix ρ N. Conceptually, it is advantageous to deal with infinite hierarchies of equations: in the sequel, we set ρ N:j = 0 whenever j > N.
11 By passing to the limit (at the formal level) in the BBGKY hierarchy as N and for j fixed; remember that U(z) = 1 N V N(z) and that V N αδ z=0 with α = Assuming that ρ N:j ρ j for N, we find that V (x)dx j = α j k=1 i t ρ j k=1 ( 2 x k 2 y k )ρ j [δ(x k z) δ(y k z)]ρ j+1 (t, X k, z, Y k, z)dz Unlike in the case of the BBGKY hierarchy, j 1 is unlimited, so that this new hierarchy has infinitely many equations.
12 Let ψ be a smooth solution of the cubic NLS equation Define then i t ψ xψ = α ψ 2 ψ ρ j (t, X j, Y j ) := j k=1 ψ(t, x k )ψ(t, y k ) We find that i t ρ ( 2 x y 2 )ρ 1 = α(ρ 1 (t, x, x) ρ 1 (t, y, y))ρ 1 More generally, a straightforward computation shows that the sequence ρ j soves the inifinite hierarchy
13 This suggests the following strategy, inspired from the derivation by Lanford of the Boltzmann equation from the classical N-body problem: a) for the N-body Schrödinger equation, pick the initial data Ψ N t=0 := N k=1 ψ (x t=0 k ) ; b) show that the sequence of marginals ρ N:j ρ j as N and for each fixed j in some suitable sense; next show that ρ j solves the infinite hierarchy by passing to the limit in the BBGKY hierarchy; c) prove that the infinite hierarchy has a unique solution which implies that ρ j (t, X j, Y j ) = j k=1 where ψ is the solution of cubic NLS. ψ(t, x k )ψ(t, y k )
14 An abstract uniqueness argument Consider the infinite hierarchy of equations u n + A n u n = L n,n+1 u n+1, u n (0) = 0, n 1 where u n takes its values in a Banach space E n ; here the linear operator L n,n+1 belongs to L(E n+1, E n ) while A n is the generator of a oneparameter group of isometries U n (t) on E n. Defining v n (t) := U n ( t)u n (t), one sees that v n(t) = U n ( t)l n,n+1 U n+1 (t)v n+1 (t), u n (0) = 0.
15 Lemma. Assume there exists C > 0 and R > 0 s.t. L n,n+1 L(En+1,E n ) Cn and u n(t) En R n for each n 1 and each t [0, T ]. Then u n 0 on [0, T ] for each n 1. Proof: Consider the decreasing scale of Banach spaces B r := and set v = (v n) n 0 E n v r = r n v n En < + n 1 n 1 F (v) := (U n ( t)l n,n+1 U n+1 (t)v n+1 ) n 1.
16 A straightforward computation shows that F (v) r1 C nr1 n v n En C n 1 n 1 r n+1 r1 n+1 r r v n 1 En C v r r r 1 We conclude by applying the abstract variant of the Cauchy-Kowalewski theorem proved by Nirenberg and Ovsyanikov. The key idea is to view B r as the analogue of the class of functions with holomorphic extension to a strip of width r. The estimate above is similar to Cauchy s inequality bearing on the derivative of a holomorphic function. Hence F behaves like a differential operator of order 1.
17 Interaction estimate The first difficulty is to find Banach spaces E n such that the interaction term L n,n+1 is bounded by O(n). Set S j := (1 xj ) 1/2 ; define E n := {ρ n L(L 2 (R n )) S 1... S n ρ n S 1... S n is Hilbert-Schmidt} which is a Hilbert space for the norm ρ n En := S 1... S n ρ n S 1... S n L 2 = n j=1 (1 xj ) 1/2 (1 yj ) 1/2 ρ n (X n, Y n ) 2 dx n dy n 1/2
18 Proposition. Let ρ E n+1 and U be a tempered distribution whose Fourier transform is bounded on R. Let σ be the integral operator with kernel σ(x n, Y n ) := U(x 1 z)ρ(x n, z, Y n, z)dz Then σ En C Û L ρ En+1 In the BBGKY hierarchy, the operator L n,n+1 is the sum of 2n terms analogous to the one treated in the proposition above. Hence L n,n+1 L(En+1,E n ) Cn V L 1
19 Sketch of the proof: Do it for the limiting interaction U = δ 0. Then σ(x n, Y n ) = ρ n+1 (X n, Y n, x 1, x 1 ) If ρ n+1 was the n+1st fold tensor product of functions of a single variable, the inequality that we want to prove reduces to the fact that H 1 (R) is an algebra. The same proof (in Fourier space variables) works for the restriction of functions of arbitrarily many variables to a subspace of arbitrary codimension, provided that cross-derivatives of these functions are bounded in L 2 this is different from the trace problem for functions in H 1 (R n ). This proof extends to the case where Û is an arbitrary function in L
20 An elementary computation shows that Set ˆσ(Ξ n, H n ) = we seek to estimate σ 2 E n = ˆρ n+1 (ξ 1 k, Ξ n 2, k l; H n, l) dkdl 4π 2 Γ n (Ξ n ) := n k=1 1 + ξ 2 k Γ n (Ξ n ) 2 Γ n (H n ) 2 ˆσ(Ξ n, H n ) 2dΞ ndh n (2π) 2n
21 Since it follows that Γ 1 (ξ 1 ) (Γ 1 (ξ 1 k) + Γ 1 (k l) + Γ 1 (l))) 1 3 Γ 1 (ξ 1 ) π 2 2 4π 2 2 ˆρ n+1 (ξ 1 k, Ξ n 2, k l; H n, l) dkdl 4π 2 Γ 1 (ξ 1 k)ˆρ n+1 (ξ 1 k, Ξ n 2, k l; H n, l) dkdl + Γ 1 (k l)ˆρ n+1 (ξ 1 k, Ξ n 2, k l; H n, l) dkdl Γ 1 (l)ˆρ n+1 (ξ 1 k, Ξ n 2, k l; H n, l) dkdl 4π 2
22 By the Cauchy-Schwarz inequality C where Γ 1 (ξ 1 k)ˆρ n+1 (ξ 1 k, Ξ n 2, k l, H n, l) dkdl 4π 2 ˆρ n+1 (ξ 1 k, Ξ n 2, k l; H n, l) 2 Γ 1 (ξ 1 k) 2 Γ 1 (k l) 2 Γ 1 (l) 2 dkdl 4π 2 C := dkdl Γ 1 (k l) 2 Γ 1 (l) 2 <. The two other terms are treated in the same manner. Therefore Γ n (Ξ n ) 2 Γ n (H n ) 2 ˆσ(Ξ n, H n ) 2 dξ ndh n (2π) 2n C Γ n 1 (Ξ n 2 )2 Γ(H n ) 2 ˆρ n+1 (ξ 1 k, Ξ n 2, k l; H n, l) 2 Γ 1 (ξ 1 k) 2 Γ 1 (k l) 2 Γ 1 (l) 2 dkdl 4π 2 with C := 3C. We conclude after changing variables: (ξ 1 k, k l, l) (ξ 1, ξ n+1, η n+1 ) 2 dξ n dh n (2π) 2n
23 Growth estimate for ρ n En Proposition. Let 0 V Cc 2 (R) and γ (0, 1); define H N = 1 2 X N + 1 k<l N N γ 1 V (N γ (x k x l )) Assume that, for each n 1 and each N N 0 (n), HN n Ψin N Ψin N M n N n with Ψ in N (X n) = N k=1 ψ in (x k ). Then, for each M 1 > M, there exists N 1 = N 1 (M 1, n) such that trace(s 1... S n ρ N,n (t)s 1... S n ) M n 1 for each t 0 and each N N 1.
24 Sketch of the proof: This is a variant of an argument by Erdös et Yau for the existence of a solution to the infinite hierarchy in space dimension 3. The only estimate involving derivatives that is propagated by the N-body equation bears on In this quantity, the typical term is H n N Ψ N Ψ N j 1 <...<j n xj1... xj1 Ψ N 2 dx N In all the other terms, either one derivative bears on V, leading to a lesser order term, or there is a multiple derivative in one of the x j s, and there are less many of such terms.
25 Set n and C ]0, 1[; one shows the existence of N 0 (C, n) st. for each N N 0 and each Ψ D(H N ) (N + H N ) n Ψ Ψ C n N n Ψ S S2 nψ This result is trivial for n = 0, 1 (since V 0 and Ψ N (t, X N ) is symmetrical in the x j s). The general case follows by induction on n: assuming the inequality proved for k = 0,..., n we prove it for n + 2. Write H N + N = N k=1 S 2 k + 1 k<l N N γ 1 V (N γ (x k x l ))
26 Define H n+1,n := H N + N Then N k=n+1 S 2 k 0. Ψ (N + H N )S S2 n(n + H N )Ψ = Ψ Sj 2 1 S S2 n S2 j 2 Ψ + 2R Ψ Sj 2 1 S S2 n H n+1,nψ n<j 1,j 2 N n<j 1 N + Ψ H n+1,n S S2 nh n+1,n Ψ Since H n+1,n S S2 n H n+1,n 0 the last term in the r.h.s. is disposed of.
27 Recall that Ψ N is symmetrical in the space variables, i.e. Ψ N (t, x σ(1),..., x σ(n) ) = Ψ N (t, x 1,..., x N ) for each σ S N Hence, denoting by W kl the multiplication by N γ V (N γ (x k x l )) acting on L 2 (R N ), one has Ψ (N + H N )S S2 n(n + H N )Ψ (N n)(n n 1) Ψ S S2 n S2 n+1 S2 n+2 Ψ +(2n + 1)(N n) Ψ S 4 1 S S2 n+1 Ψ n(n + 1)(N n) + R Ψ W 12 S1 2 N... S2 nsn+1 2 Ψ (n + 1)(N n)(n n 1) + R Ψ W 1,n+2 S1 2 N... S2 nsn+1 2 Ψ
28 By Sobolev embedding, one has the following obvious inequality W (x y) W L 1(1 xx ) Hence all the terms involving V are of a lesser order: and similarly 2R Ψ W 12 S S2 ns 2 n+1 Ψ V L 1 L (N 2γ Ψ S S2 n+1 Ψ +N γ Ψ S 4 1 S S2 n+1 Ψ ) 2R Ψ W 1,n+2 S S2 ns 2 n+1 Ψ V L 1N γ Ψ S S2 ns 2 n+1 S2 n+2 Ψ
29 Growth estimate for initial data We start from an initial data of the form that satisfies Ψ in N (X N) = N j=1 ψ in (x j ) Ψ in N ( N) n Ψ in N M n N n. We prove by induction that, if V Cc (R) and γ (0, 1 2 ), one has for each n 1 and N N (n). ( 1 2 N + U N ) n C n (N N ) n
30 Hence Ψ in N ( 1 2 N + U N ) n Ψ in N 2n 1 C n 1 M n N n for each n 1 and N N (n). To compare powers of the Hamiltonian with powers of the kinetic energy, it suffices to show that U N (N N ) 2n U N (C + C (n)n (4γ 2)n )(N N ) 2n+2 which is done by induction. One has to be careful only with the case n = 0 that sets the constant C uniformly in n. The above computation where the condition γ (0, 2 1 ) comes from.
31 Passing to the limit Let Ψ N be the solution of the N-body Schrödinger equation with factorized initial data; let ρ N be the density matrix and ρ N:n its n-th marginal. The sequence ((ρ N:n ) n 0 ) N 0 is bounded in the product space n 1 L (R, E n ) (each factor being endowed with the weak-* toplogy) On the other hand, if (ρ Nj :n) n 0 converges to (ρ n ) n 0 in that topology, the limit soves the infinite hierarchy in the sense of distributions. Notice in particular that ρ n (t, X n, Y n ) C trace(s 1... S n ρ n (t)s 1... S n ) so that ρ n L t,x n,y n.
32 The recollision term is estimated as follows N γ 1 V (N γ (x 1 x 2 ))ρ N:n (t, X n, Y n )φ(t, X n, Y n )dx n dy n dt CN γ 1 V L ρ N:n L (E n ) φ L 1 0 as N and there are 2n(n 1) such terms in the n-th equation of the infinite hierarchy. As for the interaction term, remember that E n is a Hilbert space, so that the convergence is weak and not only weak-* in the space variables. Since the linear interaction operator L n,n+1 is norm-continuous from E n+1 to E n, it is weakly continuous from E n+1 to E n.
33 NB. The convergence to a solution of the infinite hierarchy follows from a careful analysis involving the conservation of energy. The interaction operator L n,n+1 essentially reduces to taking the restriction of ρ N:n+1 to a (linear) subspace of codimension 2. But ρ N:n+1 is a trace-class operator, which allows taking the restriction to x n+1 = y n+1, with a H 1 estimate that follows from the conservation of energy; this bound allows in turn taking the further restriction x n+1 = x 1 because H 1 functions have H 1/2 L 2 restrictions to hypersurfaces. See Adami-Bardos-G.-Teta, Asympt. Anal. (2004). Analogous result in space dimension 3 (preprint by Erdös-Yau, 2004).
Mean-Field Limits for Large Particle Systems Lecture 2: From Schrödinger to Hartree
for Large Particle Systems Lecture 2: From Schrödinger to Hartree CMLS, École polytechnique & CNRS, Université Paris-Saclay FRUMAM, Marseilles, March 13-15th 2017 A CRASH COURSE ON QUANTUM N-PARTICLE DYNAMICS
More informationMean Field Limits for Interacting Bose Gases and the Cauchy Problem for Gross-Pitaevskii Hierarchies. Thomas Chen University of Texas at Austin
Mean Field Limits for Interacting Bose Gases and the Cauchy Problem for Gross-Pitaevskii Hierarchies Thomas Chen University of Texas at Austin Nataša Pavlović University of Texas at Austin Analysis and
More informationDerivation of the cubic non-linear Schrödinger equation from quantum dynamics of many-body systems
Derivation of the cubic non-linear Schrödinger equation from quantum dynamics of many-body systems The Harvard community has made this article openly available. Please share how this access benefits you.
More informationFrom many body quantum dynamics to nonlinear dispersive PDE, and back
From many body quantum dynamics to nonlinear dispersive PDE, and back ataša Pavlović (based on joint works with T. Chen, and with T. Chen and. Tzirakis) University of Texas at Austin June 18, 2013 SF-CBMS
More informationON THE UNIQUENESS OF SOLUTIONS TO THE GROSS-PITAEVSKII HIERARCHY. 1. Introduction
ON THE UNIQUENESS OF SOLUTIONS TO THE GROSS-PITAEVSKII HIERARCHY SERGIU KLAINERMAN AND MATEI MACHEDON Abstract. The purpose of this note is to give a new proof of uniqueness of the Gross- Pitaevskii hierarchy,
More informationThe Gaussian free field, Gibbs measures and NLS on planar domains
The Gaussian free field, Gibbs measures and on planar domains N. Burq, joint with L. Thomann (Nantes) and N. Tzvetkov (Cergy) Université Paris Sud, Laboratoire de Mathématiques d Orsay, CNRS UMR 8628 LAGA,
More informationDerivation of the time dependent Gross-Pitaevskii equation for the dynamics of the Bose-Einstein condensate
Derivation of the time dependent Gross-Pitaevskii equation for the dynamics of the Bose-Einstein condensate László Erdős University of Munich Evian-les-Bains, 2007 June Joint work with B. Schlein and H.T.
More informationFinite-dimensional spaces. C n is the space of n-tuples x = (x 1,..., x n ) of complex numbers. It is a Hilbert space with the inner product
Chapter 4 Hilbert Spaces 4.1 Inner Product Spaces Inner Product Space. A complex vector space E is called an inner product space (or a pre-hilbert space, or a unitary space) if there is a mapping (, )
More informationChapter 7: Bounded Operators in Hilbert Spaces
Chapter 7: Bounded Operators in Hilbert Spaces I-Liang Chern Department of Applied Mathematics National Chiao Tung University and Department of Mathematics National Taiwan University Fall, 2013 1 / 84
More informationDERIVATION OF THE CUBIC NLS AND GROSS-PITAEVSKII HIERARCHY FROM MANYBODY DYNAMICS IN d = 2, 3 BASED ON SPACETIME NORMS
DERIVATIO OF THE CUBIC LS AD GROSS-PITAEVSKII HIERARCHY FROM MAYBODY DYAMICS I d = 2, 3 BASED O SPACETIME ORMS THOMAS CHE AD ATAŠA PAVLOVIĆ Abstract. We derive the defocusing cubic Gross-Pitaevskii (GP)
More informationDerivation of Mean-Field Dynamics for Fermions
IST Austria Mathematical Many Body Theory and its Applications Bilbao, June 17, 2016 Derivation = show that solution of microscopic eq. is close to solution of effective eq. (with fewer degrees of freedom)
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 informationLow Regularity Uniqueness of Solutions to the Gross-Pitaevskii Hierarchy
Low Regularity Uniqueness of Solutions to the Gross-Pitaevskii Hierarchy Kenny Taliaferro (based on joint works with Y. Hong and Z. Xie) November 22, 2014 1 / 19 The Cubic Gross-Pitaevskii Hierarchy The
More informationWe denote the space of distributions on Ω by D ( Ω) 2.
Sep. 1 0, 008 Distributions Distributions are generalized functions. Some familiarity with the theory of distributions helps understanding of various function spaces which play important roles in the study
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 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 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 information1 Definition and Basic Properties of Compa Operator
1 Definition and Basic Properties of Compa Operator 1.1 Let X be a infinite dimensional Banach space. Show that if A C(X ), A does not have bounded inverse. Proof. Denote the unit ball of X by B and the
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 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 informationBose-Einstein condensation and limit theorems. Kay Kirkpatrick, UIUC
Bose-Einstein condensation and limit theorems Kay Kirkpatrick, UIUC 2015 Bose-Einstein condensation: from many quantum particles to a quantum superparticle Kay Kirkpatrick, UIUC/MSRI TexAMP 2015 The big
More informationFUNCTION BASES FOR TOPOLOGICAL VECTOR SPACES. Yılmaz Yılmaz
Topological Methods in Nonlinear Analysis Journal of the Juliusz Schauder Center Volume 33, 2009, 335 353 FUNCTION BASES FOR TOPOLOGICAL VECTOR SPACES Yılmaz Yılmaz Abstract. Our main interest in this
More informationAn introduction to some aspects of functional analysis
An introduction to some aspects of functional analysis Stephen Semmes Rice University Abstract These informal notes deal with some very basic objects in functional analysis, including norms and seminorms
More informationTHE UNIFORMISATION THEOREM OF RIEMANN SURFACES
THE UNIFORISATION THEORE OF RIEANN SURFACES 1. What is the aim of this seminar? Recall that a compact oriented surface is a g -holed object. (Classification of surfaces.) It can be obtained through a 4g
More informationThe Calderon-Vaillancourt Theorem
The Calderon-Vaillancourt Theorem What follows is a completely self contained proof of the Calderon-Vaillancourt Theorem on the L 2 boundedness of pseudo-differential operators. 1 The result Definition
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 informationFunctional Analysis HW #5
Functional Analysis HW #5 Sangchul Lee October 29, 2015 Contents 1 Solutions........................................ 1 1 Solutions Exercise 3.4. Show that C([0, 1]) is not a Hilbert space, that is, there
More informationSHARP BOUNDARY TRACE INEQUALITIES. 1. Introduction
SHARP BOUNDARY TRACE INEQUALITIES GILES AUCHMUTY Abstract. This paper describes sharp inequalities for the trace of Sobolev functions on the boundary of a bounded region R N. The inequalities bound (semi-)norms
More informationEffective dynamics of many-body quantum systems
Effective dynamics of many-body quantum systems László Erdős University of Munich Grenoble, May 30, 2006 A l occassion de soixantiéme anniversaire de Yves Colin de Verdiére Joint with B. Schlein and H.-T.
More informationA quantum heat equation 5th Spring School on Evolution Equations, TU Berlin
A quantum heat equation 5th Spring School on Evolution Equations, TU Berlin Mario Bukal A. Jüngel and D. Matthes ACROSS - Centre for Advanced Cooperative Systems Faculty of Electrical Engineering and Computing
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 informationTHE CORONA FACTORIZATION PROPERTY AND REFINEMENT MONOIDS
THE CORONA FACTORIZATION PROPERTY AND REFINEMENT MONOIDS EDUARD ORTEGA, FRANCESC PERERA, AND MIKAEL RØRDAM ABSTRACT. The Corona Factorization Property of a C -algebra, originally defined to study extensions
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 informationReal Variables # 10 : Hilbert Spaces II
randon ehring Real Variables # 0 : Hilbert Spaces II Exercise 20 For any sequence {f n } in H with f n = for all n, there exists f H and a subsequence {f nk } such that for all g H, one has lim (f n k,
More informationAccuracy of the time-dependent Hartree-Fock approximation
Accuracy of the time-dependent Hartree-Fock approximation Claude BARDOS, François GOLSE, Alex D. GOTTLIEB and Norbert J. MAUSER Abstract This article examines the time-dependent Hartree-Fock (TDHF) approximation
More informationGeneral Mathematics Vol. 16, No. 1 (2008), A. P. Madrid, C. C. Peña
General Mathematics Vol. 16, No. 1 (2008), 41-50 On X - Hadamard and B- derivations 1 A. P. Madrid, C. C. Peña Abstract Let F be an infinite dimensional complex Banach space endowed with a bounded shrinking
More informationSPECTRAL THEOREM FOR COMPACT SELF-ADJOINT OPERATORS
SPECTRAL THEOREM FOR COMPACT SELF-ADJOINT OPERATORS G. RAMESH Contents Introduction 1 1. Bounded Operators 1 1.3. Examples 3 2. Compact Operators 5 2.1. Properties 6 3. The Spectral Theorem 9 3.3. Self-adjoint
More information16 1 Basic Facts from Functional Analysis and Banach Lattices
16 1 Basic Facts from Functional Analysis and Banach Lattices 1.2.3 Banach Steinhaus Theorem Another fundamental theorem of functional analysis is the Banach Steinhaus theorem, or the Uniform Boundedness
More informationA NEW PROOF OF EXISTENCE OF SOLUTIONS FOR FOCUSING AND DEFOCUSING GROSS-PITAEVSKII HIERARCHIES. 1. Introduction
A EW PROOF OF EXISTECE OF SOLUTIOS FOR FOCUSIG AD DEFOCUSIG GROSS-PITAEVSKII HIERARCHIES THOMAS CHE AD ATAŠA PAVLOVIĆ Abstract. We consider the cubic and quintic Gross-Pitaevskii (GP) hierarchies in d
More informationOn the Brezis and Mironescu conjecture concerning a Gagliardo-Nirenberg inequality for fractional Sobolev norms
On the Brezis and Mironescu conjecture concerning a Gagliardo-Nirenberg inequality for fractional Sobolev norms Vladimir Maz ya Tatyana Shaposhnikova Abstract We prove the Gagliardo-Nirenberg type inequality
More informationDerivatives of Harmonic Bergman and Bloch Functions on the Ball
Journal of Mathematical Analysis and Applications 26, 1 123 (21) doi:1.16/jmaa.2.7438, available online at http://www.idealibrary.com on Derivatives of Harmonic ergman and loch Functions on the all oo
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 informationOn Friedrichs inequality, Helmholtz decomposition, vector potentials, and the div-curl lemma. Ben Schweizer 1
On Friedrichs inequality, Helmholtz decomposition, vector potentials, and the div-curl lemma Ben Schweizer 1 January 16, 2017 Abstract: We study connections between four different types of results that
More informationBehaviour of Lipschitz functions on negligible sets. Non-differentiability in R. Outline
Behaviour of Lipschitz functions on negligible sets G. Alberti 1 M. Csörnyei 2 D. Preiss 3 1 Università di Pisa 2 University College London 3 University of Warwick Lars Ahlfors Centennial Celebration Helsinki,
More informationGEOMETRIC QUANTIZATION
GEOMETRIC QUANTIZATION 1. The basic idea The setting of the Hamiltonian version of classical (Newtonian) mechanics is the phase space (position and momentum), which is a symplectic manifold. The typical
More informationPartial Differential Equations, 2nd Edition, L.C.Evans Chapter 5 Sobolev Spaces
Partial Differential Equations, nd Edition, L.C.Evans Chapter 5 Sobolev Spaces Shih-Hsin Chen, Yung-Hsiang Huang 7.8.3 Abstract In these exercises always denote an open set of with smooth boundary. As
More informationExistence and Uniqueness
Chapter 3 Existence and Uniqueness An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect
More informationTHE QUINTIC NLS AS THE MEAN FIELD LIMIT OF A BOSON GAS WITH THREE-BODY INTERACTIONS. 1. Introduction
THE QUINTIC NLS AS THE MEAN FIELD LIMIT OF A BOSON GAS WITH THREE-BODY INTERACTIONS THOMAS CHEN AND NATAŠA PAVLOVIĆ Abstract. We investigate the dynamics of a boson gas with three-body interactions in
More informationSpectral theory for compact operators on Banach spaces
68 Chapter 9 Spectral theory for compact operators on Banach spaces Recall that a subset S of a metric space X is precompact if its closure is compact, or equivalently every sequence contains a Cauchy
More informationTHE ALTERNATIVE DUNFORD-PETTIS PROPERTY FOR SUBSPACES OF THE COMPACT OPERATORS
THE ALTERNATIVE DUNFORD-PETTIS PROPERTY FOR SUBSPACES OF THE COMPACT OPERATORS MARÍA D. ACOSTA AND ANTONIO M. PERALTA Abstract. A Banach space X has the alternative Dunford-Pettis property if for every
More informationPropagation of Monokinetic Measures with Rough Momentum Profiles I
with Rough Momentum Profiles I Ecole Polytechnique Centre de Mathématiques Laurent Schwartz Quantum Systems: A Mathematical Journey from Few to Many Particles May 16th 2013 CSCAMM, University of Maryland.
More informationEigenvalues and Eigenfunctions of the Laplacian
The Waterloo Mathematics Review 23 Eigenvalues and Eigenfunctions of the Laplacian Mihai Nica University of Waterloo mcnica@uwaterloo.ca Abstract: The problem of determining the eigenvalues and eigenvectors
More informationPLEASE LET ME KNOW IF YOU FIND TYPOS (send to
Teoretisk Fysik KTH Advanced QM (SI2380), Lecture 2 (Summary of concepts) 1 PLEASE LET ME KNOW IF YOU FIND TYPOS (send email to langmann@kth.se) The laws of QM 1. I now discuss the laws of QM and their
More informationHeisenberg Uncertainty in Reduced Power Algebras
Heisenberg Uncertainty in Reduced Power Algebras Elemér E Rosinger Department of Mathematics and Applied Mathematics University of Pretoria Pretoria 0002 South Africa eerosinger@hotmail.com Abstract The
More informationbe the set of complex valued 2π-periodic functions f on R such that
. Fourier series. Definition.. Given a real number P, we say a complex valued function f on R is P -periodic if f(x + P ) f(x) for all x R. We let be the set of complex valued -periodic functions f on
More informationA Walking Tour of Microlocal Analysis
A Walking Tour of Microlocal Analysis Jeff Schonert August 10, 2006 Abstract We summarize some of the basic principles of microlocal analysis and their applications. After reviewing distributions, we then
More informationL. Levaggi A. Tabacco WAVELETS ON THE INTERVAL AND RELATED TOPICS
Rend. Sem. Mat. Univ. Pol. Torino Vol. 57, 1999) L. Levaggi A. Tabacco WAVELETS ON THE INTERVAL AND RELATED TOPICS Abstract. We use an abstract framework to obtain a multilevel decomposition of a variety
More informationThe Proper Generalized Decomposition: A Functional Analysis Approach
The Proper Generalized Decomposition: A Functional Analysis Approach Méthodes de réduction de modèle dans le calcul scientifique Main Goal Given a functional equation Au = f It is possible to construct
More informationG: Uniform Convergence of Fourier Series
G: Uniform Convergence of Fourier Series From previous work on the prototypical problem (and other problems) u t = Du xx 0 < x < l, t > 0 u(0, t) = 0 = u(l, t) t > 0 u(x, 0) = f(x) 0 < x < l () we developed
More informationCHAPTER VIII HILBERT SPACES
CHAPTER VIII HILBERT SPACES DEFINITION Let X and Y be two complex vector spaces. A map T : X Y is called a conjugate-linear transformation if it is a reallinear transformation from X into Y, and if T (λx)
More informationComplete Nevanlinna-Pick Kernels
Complete Nevanlinna-Pick Kernels Jim Agler John E. McCarthy University of California at San Diego, La Jolla California 92093 Washington University, St. Louis, Missouri 63130 Abstract We give a new treatment
More informationMath 118B Solutions. Charles Martin. March 6, d i (x i, y i ) + d i (y i, z i ) = d(x, y) + d(y, z). i=1
Math 8B Solutions Charles Martin March 6, Homework Problems. Let (X i, d i ), i n, be finitely many metric spaces. Construct a metric on the product space X = X X n. Proof. Denote points in X as x = (x,
More informationMath 5520 Homework 2 Solutions
Math 552 Homework 2 Solutions March, 26. Consider the function fx) = 2x ) 3 if x, 3x ) 2 if < x 2. Determine for which k there holds f H k, 2). Find D α f for α k. Solution. We show that k = 2. The formulas
More informationIN AN ALGEBRA OF OPERATORS
Bull. Korean Math. Soc. 54 (2017), No. 2, pp. 443 454 https://doi.org/10.4134/bkms.b160011 pissn: 1015-8634 / eissn: 2234-3016 q-frequent HYPERCYCLICITY IN AN ALGEBRA OF OPERATORS Jaeseong Heo, Eunsang
More informationHomework Assignment #5 Due Wednesday, March 3rd.
Homework Assignment #5 Due Wednesday, March 3rd. 1. In this problem, X will be a separable Banach space. Let B be the closed unit ball in X. We want to work out a solution to E 2.5.3 in the text. Work
More informationStability of an abstract wave equation with delay and a Kelvin Voigt damping
Stability of an abstract wave equation with delay and a Kelvin Voigt damping University of Monastir/UPSAY/LMV-UVSQ Joint work with Serge Nicaise and Cristina Pignotti Outline 1 Problem The idea Stability
More informationA new proof of the analyticity of the electronic density of molecules.
A new proof of the analyticity of the electronic density of molecules. Thierry Jecko AGM, UMR 8088 du CNRS, Université de Cergy-Pontoise, Département de mathématiques, site de Saint Martin, 2 avenue Adolphe
More informationHilbert space methods for quantum mechanics. S. Richard
Hilbert space methods for quantum mechanics S. Richard Spring Semester 2016 2 Contents 1 Hilbert space and bounded linear operators 5 1.1 Hilbert space................................ 5 1.2 Vector-valued
More informationMcGill University Department of Mathematics and Statistics. Ph.D. preliminary examination, PART A. PURE AND APPLIED MATHEMATICS Paper BETA
McGill University Department of Mathematics and Statistics Ph.D. preliminary examination, PART A PURE AND APPLIED MATHEMATICS Paper BETA 17 August, 2018 1:00 p.m. - 5:00 p.m. INSTRUCTIONS: (i) This paper
More informationDissipative quasi-geostrophic equations with L p data
Electronic Journal of Differential Equations, Vol. (), No. 56, pp. 3. ISSN: 7-669. URL: http://ejde.math.swt.edu or http://ejde.math.unt.edu ftp ejde.math.swt.edu (login: ftp) Dissipative quasi-geostrophic
More informationExercise Solutions to Functional Analysis
Exercise Solutions to Functional Analysis Note: References refer to M. Schechter, Principles of Functional Analysis Exersize that. Let φ,..., φ n be an orthonormal set in a Hilbert space H. Show n f n
More informationQuantum mechanics. Chapter The quantum mechanical formalism
Chapter 5 Quantum mechanics 5.1 The quantum mechanical formalism The realisation, by Heisenberg, that the position and momentum of a quantum mechanical particle cannot be measured simultaneously renders
More informationTD 1: Hilbert Spaces and Applications
Université Paris-Dauphine Functional Analysis and PDEs Master MMD-MA 2017/2018 Generalities TD 1: Hilbert Spaces and Applications Exercise 1 (Generalized Parallelogram law). Let (H,, ) be a Hilbert space.
More information4 Hilbert spaces. The proof of the Hilbert basis theorem is not mathematics, it is theology. Camille Jordan
The proof of the Hilbert basis theorem is not mathematics, it is theology. Camille Jordan Wir müssen wissen, wir werden wissen. David Hilbert We now continue to study a special class of Banach spaces,
More informationTADAHIRO OH 0, 3 8 (T R), (1.5) The result in [2] is in fact stated for time-periodic functions: 0, 1 3 (T 2 ). (1.4)
PERIODIC L 4 -STRICHARTZ ESTIMATE FOR KDV TADAHIRO OH 1. Introduction In [], Bourgain proved global well-posedness of the periodic KdV in L T): u t + u xxx + uu x 0, x, t) T R. 1.1) The key ingredient
More informationIntroduction to Index Theory. Elmar Schrohe Institut für Analysis
Introduction to Index Theory Elmar Schrohe Institut für Analysis Basics Background In analysis and pde, you want to solve equations. In good cases: Linearize, end up with Au = f, where A L(E, F ) is a
More informationIntroduction to Microlocal Analysis
Introduction to Microlocal Analysis First lecture: Basics Dorothea Bahns (Göttingen) Third Summer School on Dynamical Approaches in Spectral Geometry Microlocal Methods in Global Analysis University of
More informationNormed Vector Spaces and Double Duals
Normed Vector Spaces and Double Duals Mathematics 481/525 In this note we look at a number of infinite-dimensional R-vector spaces that arise in analysis, and we consider their dual and double dual spaces
More informationThe Heat Equation John K. Hunter February 15, The heat equation on a circle
The Heat Equation John K. Hunter February 15, 007 The heat equation on a circle We consider the diffusion of heat in an insulated circular ring. We let t [0, ) denote time and x T a spatial coordinate
More informationWEIERSTRASS THEOREMS AND RINGS OF HOLOMORPHIC FUNCTIONS
WEIERSTRASS THEOREMS AND RINGS OF HOLOMORPHIC FUNCTIONS YIFEI ZHAO Contents. The Weierstrass factorization theorem 2. The Weierstrass preparation theorem 6 3. The Weierstrass division theorem 8 References
More informationFourier Transform & Sobolev Spaces
Fourier Transform & Sobolev Spaces Michael Reiter, Arthur Schuster Summer Term 2008 Abstract We introduce the concept of weak derivative that allows us to define new interesting Hilbert spaces the Sobolev
More informationHilbert Sixth Problem
Academia Sinica, Taiwan Stanford University Newton Institute, September 28, 2010 : Mathematical Treatment of the Axioms of Physics. The investigations on the foundations of geometry suggest the problem:
More informationANALYSIS QUALIFYING EXAM FALL 2017: SOLUTIONS. 1 cos(nx) lim. n 2 x 2. g n (x) = 1 cos(nx) n 2 x 2. x 2.
ANALYSIS QUALIFYING EXAM FALL 27: SOLUTIONS Problem. Determine, with justification, the it cos(nx) n 2 x 2 dx. Solution. For an integer n >, define g n : (, ) R by Also define g : (, ) R by g(x) = g n
More informationG : Quantum Mechanics II
G5.666: Quantum Mechanics II Notes for Lecture 5 I. REPRESENTING STATES IN THE FULL HILBERT SPACE Given a representation of the states that span the spin Hilbert space, we now need to consider the problem
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 informationTheory of PDE Homework 2
Theory of PDE Homework 2 Adrienne Sands April 18, 2017 In the following exercises we assume the coefficients of the various PDE are smooth and satisfy the uniform ellipticity condition. R n is always an
More informationThis ODE arises in many physical systems that we shall investigate. + ( + 1)u = 0. (λ + s)x λ + s + ( + 1) a λ. (s + 1)(s + 2) a 0
Legendre equation This ODE arises in many physical systems that we shall investigate We choose We then have Substitution gives ( x 2 ) d 2 u du 2x 2 dx dx + ( + )u u x s a λ x λ a du dx λ a λ (λ + s)x
More informationCommutative Banach algebras 79
8. Commutative Banach algebras In this chapter, we analyze commutative Banach algebras in greater detail. So we always assume that xy = yx for all x, y A here. Definition 8.1. Let A be a (commutative)
More informationMAT 449 : Problem Set 7
MAT 449 : Problem Set 7 Due Thursday, November 8 Let be a topological group and (π, V ) be a unitary representation of. A matrix coefficient of π is a function C of the form x π(x)(v), w, with v, w V.
More informationFriedrich symmetric systems
viii CHAPTER 8 Friedrich symmetric systems In this chapter, we describe a theory due to Friedrich [13] for positive symmetric systems, which gives the existence and uniqueness of weak solutions of boundary
More informationOn the pair excitation function.
On the pair excitation function. Joint work with M. Grillakis based on our 2013 and 2016 papers Beyond mean field: On the role of pair excitations in the evolution of condensates, Journal of fixed point
More informationON PERIODIC SOLUTIONS TO SOME LAGRANGIAN SYSTEM WITH TWO DEGREES OF FREEDOM
ON PERIODIC SOLUTIONS TO SOME LAGRANGIAN SYSTEM WITH TWO DEGREES OF FREEDOM OLEG ZUBELEVICH DEPT. OF THEORETICAL MECHANICS, MECHANICS AND MATHEMATICS FACULTY, M. V. LOMONOSOV MOSCOW STATE UNIVERSITY RUSSIA,
More informationON THE MEAN-FIELD AND CLASSICAL LIMITS OF QUANTUM MECHANICS
O THE MEA-FIELD AD CLASSICAL LIMITS OF QUATUM MECHAICS FRAÇOIS GOLSE, CLÉMET MOUHOT, AD THIERRY PAUL Abstract. The main result in this paper is a new inequality bearing on solutions of the -body linear
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 informationDETERMINATION OF THE BLOW-UP RATE FOR THE SEMILINEAR WAVE EQUATION
DETERMINATION OF THE LOW-UP RATE FOR THE SEMILINEAR WAVE EQUATION y FRANK MERLE and HATEM ZAAG Abstract. In this paper, we find the optimal blow-up rate for the semilinear wave equation with a power nonlinearity.
More informationNOTES ON NEWLANDER-NIRENBERG THEOREM XU WANG
NOTES ON NEWLANDER-NIRENBERG THEOREM XU WANG Abstract. In this short note we shall recall the classical Newler-Nirenberg theorem its vector bundle version. We shall also recall an L 2 -Hörmer-proof given
More informationProperties of the Scattering Transform on the Real Line
Journal of Mathematical Analysis and Applications 58, 3 43 (001 doi:10.1006/jmaa.000.7375, available online at http://www.idealibrary.com on Properties of the Scattering Transform on the Real Line Michael
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 informationDeterminant lines and determinant line bundles
CHAPTER Determinant lines and determinant line bundles This appendix is an exposition of G. Segal s work sketched in [?] on determinant line bundles over the moduli spaces of Riemann surfaces with parametrized
More informationChapter One. The Calderón-Zygmund Theory I: Ellipticity
Chapter One The Calderón-Zygmund Theory I: Ellipticity Our story begins with a classical situation: convolution with homogeneous, Calderón- Zygmund ( kernels on R n. Let S n 1 R n denote the unit sphere
More information