1,395 research outputs found
Decoupling of Degenerate Positive-norm States in Witten's String Field Theory
We show that the degenerate positive-norm physical propagating fields of the
open bosonic string can be gauged to the higher rank fields at the same mass
level. As a result, their scattering amplitudes can be determined from those of
the higher spin fields. This phenomenon arises from the existence of two types
of zero-norm states with the same Young representations as those of the
degenerate positive-norm states in the old covariant first quantized (OCFQ)
spectrum. This is demonstrated by using the lowest order gauge transformation
of Witten's string field theory (WSFT) up to the fourth massive level
(spin-five), and is found to be consistent with conformal field theory
calculation based on the first quantized generalized sigma-model approach. In
particular, on-shell conditions of zero-norm states in OCFQ stringy gauge
transformation are found to correspond, in a one-to-one manner, to the
background ghost fields in off-shell gauge transformation of WSFT. The
implication of decoupling of scalar modes on Sen's conjectures was also briefly
discussed.Comment: 18 pages, use Latex with revtex
The sTB-B Hierarchy
We construct a new supersymmetric two boson (sTB-B) hierarchy and study its
properties. We derive the conserved quantities and the Hamiltonian structures
(proving the Jacobi identity) for the system. We show how this system gives the
sKdV-B equation and its Hamiltonian structures upon appropriate reduction. We
also describe the zero curvature formulation of this hierarchy both in the
superspace as well as in components.Comment: 15 pages, Te
Semilinear mixed problems on Hilbert complexes and their numerical approximation
Arnold, Falk, and Winther recently showed [Bull. Amer. Math. Soc. 47 (2010),
281-354] that linear, mixed variational problems, and their numerical
approximation by mixed finite element methods, can be studied using the
powerful, abstract language of Hilbert complexes. In another recent article
[arXiv:1005.4455], we extended the Arnold-Falk-Winther framework by analyzing
variational crimes (a la Strang) on Hilbert complexes. In particular, this gave
a treatment of finite element exterior calculus on manifolds, generalizing
techniques from surface finite element methods and recovering earlier a priori
estimates for the Laplace-Beltrami operator on 2- and 3-surfaces, due to Dziuk
[Lecture Notes in Math., vol. 1357 (1988), 142-155] and later Demlow [SIAM J.
Numer. Anal., 47 (2009), 805-827], as special cases. In the present article, we
extend the Hilbert complex framework in a second distinct direction: to the
study of semilinear mixed problems. We do this, first, by introducing an
operator-theoretic reformulation of the linear mixed problem, so that the
semilinear problem can be expressed as an abstract Hammerstein equation. This
allows us to obtain, for semilinear problems, a priori solution estimates and
error estimates that reduce to the Arnold-Falk-Winther results in the linear
case. We also consider the impact of variational crimes, extending the results
of our previous article to these semilinear problems. As an immediate
application, this new framework allows for mixed finite element methods to be
applied to semilinear problems on surfaces.Comment: 22 pages; v2: major revision, particularly sharpening of error
estimates in Section
On the Electric Charge of Monopoles at Finite Temperature
We calculate the electric charge at finite temperature for non-Abelian
monopoles in spontaneously broken gauge theories with a CP violating
-term. A careful treatment of dyon's gauge degrees of freedom shows
that Witten formula for the dyon charge at , ,
remains valid at .Comment: 13 pages, latex file, no figure
Background field quantization and non-commutative Maxwell theory
We quantize non-commutative Maxwell theory canonically in the background
field gauge for weak and slowly varying background fields. We determine the
complete basis for expansion under such an approximation. As an application, we
derive the Wigner function which determines the leading order high temperature
behavior of the perturbative amplitudes of non-commutative Maxwell theory. To
leading order, we also give a closed form expression for the distribution
function for the non-commutative gauge theory at high temperature.Comment: 9 pages, title slightly modified, to appear in Physics Letters
Superconductivity by long-range color magnetic interaction in high-density quark matter
We argue that in quark matter at high densities, the color magnetic field
remains unscreened and leads to the phenomenon of color superconductivity.
Using the renormalization group near the Fermi surface, we find that the
long-range nature of the magnetic interaction changes the asymptotic behavior
of the gap at large chemical potential qualitatively. We find
, where is the
small gauge coupling. We discuss the possibility of breaking rotational
symmetry by the formation of a condensate with nonzero angular momentum, as
well as interesting parallels to some condensed matter systems with long-range
forces.Comment: 14 pages, REVTEX, uses eps
On the Resummation of the epe^+e^-$ Annihilation
The resummation of the non-singlet contributions is
performed for initial state QED corrections. As examples, the effect of the
resummation on neutral-current deep-inelastic scattering and the scattering cross section near the -peak is
investigated.Comment: 11 pages Latex, including 3 eps-figure
Imprints of Short Distance Physics On Inflationary Cosmology
We analyze the impact of certain modifications to short distance physics on
the inflationary perturbation spectrum. For the specific case of power-law
inflation, we find distinctive -- and possibly observable -- effects on the
spectrum of density perturbations.Comment: Revtex 4, 3 eps figs, 4 page
Dynamics and Thermodynamics of Systems with Long Range Interactions: an Introduction
We review theoretical results obtained recently in the framework of
statistical mechanics to study systems with long range forces. This fundamental
and methodological study leads us to consider the different domains of
applications in a trans-disciplinary perspective (astrophysics, nuclear
physics, plasmas physics, metallic clusters, hydrodynamics,...) with a special
emphasis on Bose-Einstein condensates.Comment: Chapter of the forthcoming "Lecture Notes in Physics" volume:
``Dynamics and Thermodynamics of Systems with Long Range Interactions'', T.
Dauxois, S. Ruffo, E. Arimondo, M. Wilkens Eds., Lecture Notes in Physics
Vol. 602, Springer (2002). (see http://link.springer.de/series/lnpp/
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