34 research outputs found
Absence of exponentially localized solitons for the Novikov-Veselov equation at positive energy
In this note we show that the Novikov-Veselov equation at positive energy (an
analog of KdV in 2+1 dimensions) has no exponentially localized solitons ( in
the two-dimensional sense)
The inverse scattering problem on a fixed energy level for the two-dimensional Schrödinger operator
AbstractThis paper contains a solution with complete proofs of the main problems of the inverse scattering at fixed energy E for the Schrödinger two-dimensional operator with decreasing coefficients (uniqueness of the reconstruction, a reconstruction procedure, characterization of the scattering data). Most completed results are obtained under the condition of “smallness” of coefficients in comparison with the number E. This paper develops and generalizes several preceded papers
(Anti-)de Sitter Black Hole Thermodynamics and the Generalized Uncertainty Principle
We extend the derivation of the Hawking temperature of a Schwarzschild black
hole via the Heisenberg uncertainty principle to the de Sitter and anti-de
Sitter spacetimes. The thermodynamics of the Schwarzschild-(anti-)de Sitter
black holes is obtained from the generalized uncertainty principle of string
theory and non-commutative geometry. This may explain why the thermodynamics of
(anti-)de Sitter-like black holes admits a holographic description in terms of
a dual quantum conformal field theory, whereas the thermodynamics of
Schwarzschild-like black holes does not.Comment: 10 pages, revtex
Inverse scattering at fixed energy on surfaces with Euclidean ends
On a fixed Riemann surface with Euclidean ends and genus ,
we show that, under a topological condition, the scattering matrix S_V(\la)
at frequency \la > 0 for the operator determines the potential
if for all
and for some , where denotes the distance
from to a fixed point . The topological condition is given by
for and by if . In \rr^2 this
implies that the operator S_V(\la) determines any potential
such that for all .Comment: 21 page
Novel Approach to Confront Electroweak Data and Theory
A novel approach to study electroweak physics at one-loop level in generic
theories is introduced. It separates the 1-loop
corrections into two pieces: process specific ones from vertex and box
contributions, and universal ones from contributions to the gauge boson
propagators. The latter are parametrized in terms of four effective form
factors , , and corresponding to the , , and
propagators. Under the assumption that only the Standard Model contributes to
the process specific corrections, the magnitudes of the four form factors are
determined at and at q^2=\mmz by fitting to all available precision
experiments. These values are then compared systematically with predictions of
theories. In all fits \alpha_s(\mz) and
\bar{\alpha}(\mmz) are treated as external parameters in order to keep the
interpretation as flexible as possible. The treatment of the electroweak data
is presented in detail together with the relevant theoretical formulae used to
interpret the data. No deviation from the Standard Model has been identified.
Ranges of the top quark and Higgs boson masses are derived as functions of
\alpha_s(\mz) and \bar{\alpha}(\mmz). Also discussed are consequences of
the recent precision measurement of the left-right asymmetry at SLC as well as
the impact of a top quark mass and an improved mass measurement.Comment: 123 pages, LaTeX (33 figures available via anonymous ftp),
KEK-TH-375, KEK preprint 93-159, KANAZAWA-94-19, DESY 94-002, YUMS 94-22,
SNUTP 94-82, to be published in Z.Phys.
The Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is a second generation water Cherenkov
detector designed to determine whether the currently observed solar neutrino
deficit is a result of neutrino oscillations. The detector is unique in its use
of D2O as a detection medium, permitting it to make a solar model-independent
test of the neutrino oscillation hypothesis by comparison of the charged- and
neutral-current interaction rates. In this paper the physical properties,
construction, and preliminary operation of the Sudbury Neutrino Observatory are
described. Data and predicted operating parameters are provided whenever
possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and
epsf style files. For additional information about SNO see
http://www.sno.phy.queensu.ca . This version has some new reference