1,253 research outputs found
A path integral derivation of -genus
The formula for the Hirzebruch -genus of complex manifolds is a
consequence of the Hirzebruch-Riemann-Roch formula. The classical index
formulae for Todd genus, Euler number, and Signature correspond to the case
when the complex variable 0, -1, and 1 respectively. Here we give a {\it
direct} derivation of this nice formula based on supersymmetric quantum
mechanics.Comment: 5 page
New Implications of Lorentz Violation
In this proceedings, I summarize two recently discovered theoretical
implications that Lorentz violation has on physical systems. First, I discuss
new models for neutrino oscillations in which relatively simple combinations of
Lorentz-violating parameters can mimic the major features of the current
neutrino oscillation data. Second, I will present results on Yang-Mills
instantons in Lorentz-violating background fields. An explicit solution is
presented for unit winding number in SU(2).Comment: 8 pages, proceedings for 2003 Coral Gables Conference, Ft.
Lauderdale, F
Multi-Periodic Coherent States and the WKB-Exactness
We construct the path integral formula in terms of ``multi-periodic''
coherent state as an extension of the Nielsen-Rohrlich formula for spin. We
make an exact calculation of the formula and show that, when a parameter
corresponding to the magnitude of spin becomes large, the leading order term of
the expansion coincides with the exact result. We also give an explicit
correspondence between the trace formula in the multi-periodic coherent state
and the one in the ``generalized'' coherent state.Comment: 28 pages, late
Multi-Periodic Coherent States and the WKB-Exactness II ``Non-compact Case and Classical theories Revisited''
We show that the WKB approximation gives the exact result in the trace
formula of ``'', which is the non-compact counterpart of , in terms
of the ``multi-periodic'' coherent state. We revisit the symplectic 2-forms on
and and, especially, construct that on with the unitary
form. We also revisit the exact calculation of the classical patition functions
of them.Comment: LaTeX, 29 page
A Newman-Penrose Calculator for Instanton Metrics
We present a Maple11+GRTensorII based symbolic calculator for instanton
metrics using Newman-Penrose formalism. Gravitational instantons are exact
solutions of Einstein's vacuum field equations with Euclidean signature. The
Newman-Penrose formalism, which supplies a toolbox for studying the exact
solutions of Einstein's field equations, was adopted to the instanton case and
our code translates it for the computational use.Comment: 13 pages. Matches the published version. The web page of the codes is
changed as https://github.com/tbirkandan/NPInstanto
Possible Origin of Fermion Chirality and Gut Structure From Extra Dimensions
The fundamental chiral nature of the observed quarks and leptons and the
emergence of the gauge group itself are most puzzling aspects of the standard
model. Starting from general considerations of topological properties of gauge
field configurations in higher space-time dimensions, it is shown that the
existence of non-trivial structures in ten dimensions would determine a class
of models corresponding to a grand unified GUT structure with complex fermion
representations with respect to . The
discussion is carried out within the framework of string theories with
characteristic energy scales below the Planck mass. Avoidance of topological
obstructions upon continuous deformation of field configurations leads to
global chiral symmetry breaking of the underlying fundamental theory, imposes
rigorous restrictions on the structure of the vacuum and space-time itself and
determines uniquely the gauge structure and matter content.Comment: final version to appear in Phys. Rev.
Equivariance, BRST and Superspace
The structure of equivariant cohomology in non-abelian localization formulas
and topological field theories is discussed. Equivariance is formulated in
terms of a nilpotent BRST symmetry, and another nilpotent operator which
restricts the BRST cohomology onto the equivariant, or basic sector. A
superfield formulation is presented and connections to reducible (BFV)
quantization of topological Yang-Mills theory are discussed.Comment: (24 pages, report UU-ITP and HU-TFT-93-65
The unified Skyrmion profiles and Static Properties of Nucleons
An unified approximated solution for symmetric Skyrmions was proposed for the
SU(2) Skyrme model for baryon numbers up to 8,which take the hybrid form of a
kink-like solution and that given by the instanton method. The Skyrmion
profiles are examined by computing lowest soliton energy as well as the static
properties of nucleons within the framework of collective quantization, with a
good agreement with the exact numeric results. The comparisons with the
previous computations as well as the experimental data are also given.Comment: 6 pages, 3 figures, 3 tables, Created by LaTex Syste
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