32,746 research outputs found
The Functional Integral for a Free Particle on a Half-Plane
A free non-relativistic particle moving in two dimensions on a half-plane can
be described by self-adjoint Hamiltonians characterized by boundary conditions
imposed on the systems. The most general boundary condition is parameterized in
terms of the elements of an infinite-dimensional matrix. We construct the
Brownian functional integral for each of these self-adjoint Hamiltonians.
Non-local boundary conditions are implemented by allowing the paths striking
the boundary to jump to other locations on the boundary. Analytic continuation
in time results in the Green's functions of the Schrodinger equation satisfying
the boundary condition characterizing the self-adjoint Hamiltonian.Comment: 16 page
Solving the shallow water equations on the Cray X-MP/48 and the connection machine 2
The shallow water equations in Cartesian coordinates and 2-D are solved on the Connection Machine 2 (CM-2) using both the spectral and finite difference methods. A description of these implementations is presented together with a brief discussion of the CM-2 as it relates to these specific computations. The finite difference code was written both in C* and *LISP and the spectral code was written in *LISP. The performance of the codes is compared with a FORTRAN version that was optimized for the Cray X-MP/48
Phenomenology of Neutrino Mass Matrix
The search for possible mixing patterns of charged leptons and neutrinos is
important to get clues of the origin of nearly maximal mixings, since there are
some preferred bases of the lepton mass matrices given by underlying theories.
We systematically examine the mixing patterns which could lead to large lepton
mixing angles. We find out 37 mixing patterns are consistent with experimental
data if taking into account phase factors in the mixing matrices. Only 6
patterns of them can explain the observed data without any tuning of
parameters, while the others need particular choices for phase values.Comment: revised reference
On correlation functions of integrable models associated to the six-vertex R-matrix
We derive an analog of the master equation obtained recently for correlation
functions of the XXZ chain for a wide class of quantum integrable systems
described by the R-matrix of the six-vertex model, including in particular
continuum models. This generalized master equation allows us to obtain multiple
integral representations for the correlation functions of these models. We
apply this method to derive the density-density correlation functions of the
quantum non-linear Schrodinger model.Comment: 21 page
Spin Susceptibility in the Superconducting state of Ferromagnetic Superconductor UCoGe
In order to determine the superconducting paring state in the ferromagnetic
superconductor UCoGe, ^{59}Co NMR Knight shift, which is directly related to
the microscopic spin susceptibility, was measured in the superconducting state
under magnetic fields perpendicular to spontaneous magnetization axis:
^{59}K^{a, b}. ^{59}K^{a, b} shows to be constant, but does not decrease below
a superconducting transition. These behaviors as well as the invariance of the
internal field at the Co site in the superconducting state exclude the
spin-singlet pairing, and can be interpreted with the equal-spin pairing state
with a large exchange field along the c axis, which was studied by Mineev
[Phys. Rev. B 81, 180504 (2010)].Comment: 5 pages, 4 figures, to be appear in PR
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