Mathematics Problem Archive

Showing 1-27 of 27 problems

AMR-077-0001
Partially Solved

Soft Phases in Two-Dimensional O(N) Models

v1.3 research notes

Do spin correlations in the classical Heisenberg model, and other $O(N)$ models with $N>2$, decay exponentially at every nonzero temperature, or do th...

L3
Mathematical Physics
AMR-077-0004
Partially Solved

Long-Range Order for the Quantum Heisenberg Model

v1.3 research notes

(A) Prove long-range order for the quantum Heisenberg ferromagnet in dimension $D>2$ at temperature $T>0$. (B) Prove long-range order for spin $1/2$ i...

L3
Mathematical Physics
AMR-077-0005
Partially Solved

Extended States with Extensive Disorder

v1.3 research notes

Establish, in some energy range, the existence of extended eigenstates or continuous spectrum for linear operators with extensive disorder, such as a ...

L3
Mathematical Physics
AMR-077-0007
Partially Solved

One-Dimensional Fermi Gas with Attractive Interaction

v1.3 research notes

Determine the large-distance behavior of the one-particle reduced density matrix for a one-dimensional Fermi gas with spin and attractive interaction....

L3
Mathematical Physics
AMR-077-0008
Partially Solved

Entropy Production in Nonequilibrium Statistical Mechanics

v1.3 research notes

Give a fundamental and experimentally accessible definition of the entropy creation rate for general classical systems in stationary nonequilibrium st...

L3
Mathematical Physics
AMR-077-0009
Partially Solved

Separatrix Splitting under Quasiperiodic Forcing

v1.3 research notes

Find an asymptotic expression for the splitting of the separatrix of a quasiperiodically forced pendulum in the regime where the perturbation series i...

L4
Mathematical Physics
AMR-077-0014
Partially Solved

Meaning and Impossibility of Exact Helium Energy Levels

v1.3 research notes

Give a mathematically precise meaning to determining the energy levels of the helium atom exactly, in the sense that hydrogen energy levels are exact,...

L3
Mathematical Physics
AMR-078-0008
Partially Solved

Absolutely Continuous Spectrum Under a Weighted L2 Condition

v1.3 research notes

Let $V$ be a function on $\mathbb R^\nu$, $\nu\geq2$, satisfying $\int |x|^{-\nu+1}|V(x)|^2\,d^\nu x<\infty$. Prove that $-\Delta+V$ has absolutely co...

L3
Mathematical Physics
AMR-078-0009
Partially Solved

Bounded Excess Electrons

v1.3 research notes

For the $N$-electron Coulomb Hamiltonian with nuclear charge $Z$, let $N_0(Z)$ be the least $N$ after which adding electrons no longer lowers the grou...

L3
Mathematical Physics
AMR-078-0012
Partially Solved

First-Principles Molecular Configurations

v1.3 research notes

Give a mathematically rigorous justification of the techniques used to determine molecular configurations from first principles....

L3
Mathematical Physics
AMR-078-0014
Partially Solved

Continuity of the Integrated Density of States

v1.3 research notes

Prove that the integrated density of states $k(E)$ is continuous as a function of the energy $E$....

L3
Mathematical Physics
AMR-078-0015
Partially Solved

One-Dimensional Lieb-Thirring Constants

v1.3 research notes

For spatial dimension $\nu=1$ and $1/2<\gamma<3/2$, determine the optimal constants $L_{\gamma,1}$ in the Lieb-Thirring inequality as predicted by the...

L3
Mathematical Physics
AMR-079-0003
Partially Solved

Riemann-Hilbert Problem with non-analytic data

v1.3 research notes

In many situations one is concerned with the asymptotic behavior of Riemann-Hilbert problems with exponentially varying data of the form $e^{in\phi(z)...

L3
Mathematical Physics
AMR-079-0005
Partially Solved

Multivariate analysis

v1.3 research notes

Random matrix theory was introduced into theoretical physics by Wigner in the 1950s in his study of neutron scattering resonances, but as a subject, R...

L3
Mathematical Physics
AMR-079-0006
Partially Solved

$\beta$-ensembles

v1.3 research notes

Random point processes corresponding to $\beta$-ensembles, or, equivalently, log gases at inverse temperature $\beta$, are defined for arbitrary $\bet...

L4
Mathematical Physics
AMR-079-0007
Partially Solved

Non-self adjoint spectral problems

v1.3 research notes

Much is now known, theoretically and also numerically, about the spectrum of self-adjoint operators. This is in great contrast to the situation regard...

L3
Mathematical Physics
AMR-079-0008
Partially Solved

Long-time behavior with non-generic initial data

v1.3 research notes

The long-time behavior of the solution of the Cauchy problem for a great many integrable systems on the line is now well-understood, using, for exampl...

L3
Mathematical Physics
AMR-079-0009
Partially Solved

The parking problem

v1.3 research notes

A number of so-called ``transportation'' problems have now been analyzed in terms of RMT. These include: the ``vicious'' walker problem of M. Fisher, ...

L3
Mathematical Physics
AMR-079-0011
Partially Solved

The Toda lattice with random initial data

v1.3 research notes

Let $J$ be a random tridiagonal matrix drawn from the tridiagonal Gaussian orthogonal ensemble and evolve it by the finite nonperiodic Toda flow, so i...

L3
Mathematical Physics
AMR-079-0012
Partially Solved

Perturbation theory for infinite dimensional integrable systems

v1.3 research notes

The bijective mapping properties of the scattering transform for a variety of integrable systems on the line between appropriate weighted Sobolev spac...

L3
Mathematical Physics
AMR-079-0014
Partially Solved

Initial/boundary value problems for integrable systems

v1.3 research notes

In the late 1990s Fokas introduced a new, more flexible approach to inverse scattering theory, and in recent years a number of researchers (Fokas, Its...

L3
Mathematical Physics
AMR-079-0015
Partially Solved

Multi-matrix models and models with an external field

v1.3 research notes

There has been considerable progress (Kuijlaars,...) in understanding basic statistics such as the correlation functions for the 2-matrix random matri...

L3
Mathematical Physics
AMR-080-0001
Partially Solved

KdV with almost periodic initial data

v1.3 research notes

Consider the Korteweg--de Vries (KdV) equation u_t + u u_x + u_{xxx} =0 with initial data u(x, t=0) = u_0(x),\qquad x\in \mathbb{R}. In the 1970's, Mc...

L4
Mathematical Physics
AMR-080-0003
Partially Solved

interacting particle systems and KPZ

v1.3 research notes

In 1999, J. All these early examples were ``integrable'' in the sense that certain powerful algebraic tools, e.g., determinantal particle systems, the...

L4
Mathematical Physics
AMR-080-0004
Partially Solved

numerical computation with random data

v1.3 research notes

Standard algorithms to compute the eigenvalues of a random matrix $H$ are completely integrable Hamiltonian systems (see ). The question raised in was...

L3
Mathematical Physics
AMR-080-0005
Partially Solved

initial boundary value problems for integrable systems (IBVP)

v1.3 research notes

Initial boundary value problems for integrable systems in $1+1$ dimensions are of great interest. It turns out, however, that in Fokas' approach the g...

L4
Mathematical Physics
AMR-080-0006
Partially Solved

numerical solution of integrable systems

v1.3 research notes

Solutions of the Cauchy problem for linear dispersive equations can be expressed in terms of Fourier integral operators. This is a very challenging pr...

L4
Mathematical Physics