7 research outputs found
Wigner quantization of some one-dimensional Hamiltonians
Recently, several papers have been dedicated to the Wigner quantization of
different Hamiltonians. In these examples, many interesting mathematical and
physical properties have been shown. Among those we have the ubiquitous
relation with Lie superalgebras and their representations. In this paper, we
study two one-dimensional Hamiltonians for which the Wigner quantization is
related with the orthosymplectic Lie superalgebra osp(1|2). One of them, the
Hamiltonian H = xp, is popular due to its connection with the Riemann zeros,
discovered by Berry and Keating on the one hand and Connes on the other. The
Hamiltonian of the free particle, H_f = p^2/2, is the second Hamiltonian we
will examine. Wigner quantization introduces an extra representation parameter
for both of these Hamiltonians. Canonical quantization is recovered by
restricting to a specific representation of the Lie superalgebra osp(1|2)
Lower Spectral Branches of a Particle Coupled to a Bose Field
The structure of the lower part (i.e. -away below the two-boson
threshold) spectrum of Fr\"ohlich's polaron Hamiltonian in the weak coupling
regime is obtained in spatial dimension . It contains a single polaron
branch defined for total momentum , where is a bounded domain, and, for any , a
manifold of polaron + one-boson states with boson momentum in a bounded
domain depending on . The polaron becomes unstable and dissolves into the
one boson manifold at the boundary of . The dispersion laws and
generalized eigenfunctions are calculated
Evidence of American Martens Populating the Turtle Mountains of North Dakota
American martens (Martes americana) were native to northeastern North Dakota but were considered extirpated by the early 1800s. Although there is no historic evidence of martens occurring beyond the northeast, forested habitat potentially suitable for martens exists in the Turtle Mountains region of northcentral North Dakota and southwestern Manitoba. From 1989– 1991, the Turtle Mountain Trappers Association translocated 59 martens into the Canadian portion of the Turtle Mountains. During summer 2007, we used covered track-plates and/or remotely-triggered cameras placed at 123 survey sites distributed among 41 1-km2 grid cells (a GIS-generated layer imposed on electronic maps of the study region) to determine if martens occupied the Turtle Mountains in North Dakota. Martens were detected at 26 (21%) sites, representing 20 of the 41 sample cells (49%) widely dispersed throughout the study area. Our study provided the first evidence of martens occurring in North Dakota since the early 1800s
On metric-connection compatibility and the signature change of space-time
We discuss and investigate the problem of existence of metric-compatible
linear connections for a given space-time metric which is, generally, assumed
to be semi-pseudo-Riemannian. We prove that under sufficiently general
conditions such connections exist iff the rank and signature of the metric are
constant. On this base we analyze possible changes of the space-time signature.Comment: 18 standard LaTeX 2e pages. The packages AMS-LaTeX and amsfonts are
require
Evidence of American Martens Populating the Turtle Mountains of North Dakota
American martens (Martes americana) were native to northeastern North Dakota but were considered extirpated by the early 1800s. Although there is no historic evidence of martens occurring beyond the northeast, forested habitat potentially suitable for martens exists in the Turtle Mountains region of northcentral North Dakota and southwestern Manitoba. From 1989– 1991, the Turtle Mountain Trappers Association translocated 59 martens into the Canadian portion of the Turtle Mountains. During summer 2007, we used covered track-plates and/or remotely-triggered cameras placed at 123 survey sites distributed among 41 1-km2 grid cells (a GIS-generated layer imposed on electronic maps of the study region) to determine if martens occupied the Turtle Mountains in North Dakota. Martens were detected at 26 (21%) sites, representing 20 of the 41 sample cells (49%) widely dispersed throughout the study area. Our study provided the first evidence of martens occurring in North Dakota since the early 1800s