Here are some clues from two journals, one print and one electronic.
from American Institute of Physics - about American Journal of Mathematical Physics --->
http://jmp.aip.org/jmp/staff.jsp
Focus and Coverage
Journal of Mathematical Physics is published monthly by the American Institute of Physics. Its purpose is the publication of papers in mathematical physics – that is, the application of mathematics to problems in physics and the development of mathematical methods suitable for such applications and for the formulation of physical theories. The mathematics should be written in a manner that is understandable to theoretical physicists. Occasionally, reviews of mathematical subjects relevant to physics and special issues combining papers on a topic of current interest may be published.
Journal of Mathematical Physics welcomes original research of the highest quality in all active areas of mathematical physics, including the following:
Classical Mechanics
Conformal Field Theory
Dynamical Systems
Electromagnetic Theory (mathematical aspects)
Ergodic Theory
Fluid Mechanics (Navier–Stokes equations, models of turbulence)
Gauge Field Theory
General Relativity
Gravitation Theory (classical and quantum)
KAM Theory (stability and chaos)
Kinetic Theory
Many-Body Theory
Mathematical Methods in Condensed Matter Physics
Methods in Mathematical Physics
Nonlinear Partial Differential Equations in Mathematical Physics
Percolation Models
Quantum Chaos
Quantum Computing
Quantum Field Theory (algebraic and constructive)
Quantum Mechanics
Renormalization
Scattering Theory (classical and quantum)
Schrödinger Equation (mathematical properties)
Semiclassical Analysis
Spectral Theory
Statistical Mechanics (equilibrium and nonequilibrium)
String and Brane Theory
Symmetries
Symplectic Dynamics
Supersymmetry
from Mathematical Physics Electronic Journal --->
http://www.ma.utexas.edu/mpej/
"The research subjects will be primarily on Mathematical Physics; but this should not be interpreted as a limitation, as the editors feel that essentially all subjects of Mathematics and Physics are in principle relevant to Mathematical Physics"
(some MPEJ editorial board specialties)
Celestial mechanics
Cellular automata
Classical mechanics
Computer-assisted proofs
C*-algebras
Dynamical systems
Ergodic theory
Interacting particle systems
K-theory
KAM theory
Mathematical problems in solid state physics
Noncommutative geometry
Nonlinear elliptic equations
Nonlinear differential difference equations
Nonlinear partial differential equations
Nonlinear waves
Perturbation theory for Ordinary Differential Equations
Quantum field theory
Quantum mechanics
Schrodinger operators
Statistical mechanics
Stochastic processes
[EDIT]small correction to first list