647 research outputs found
Uniformly accelerating observer in -deformed space-time
In this paper, we study the effect of -deformation of the space-time
on the response function of a uniformly accelerating detector coupled to a
scalar field. Starting with -deformed Klein-Gordon theory, which is
invariant under a -Poincar\'e algebra and written in commutative
space-time, we derive -deformed Wightman functions, valid up to second
order in the deformation parameter . Using this, we show that the first
non-vanishing correction to the Unruh thermal distribution is only in the
second order in . We also discuss various other possible sources of
-dependent corrections to this thermal distribution.Comment: 12 pages, minor changes, to appear in Phys. Rev.
Newton's Equation on the kappa space-time and the Kepler problem
We study the modification of Newton's second law, upto first order in the
deformation parameter , in the -space-time. We derive the deformed
Hamiltonian, expressed in terms of the commutative phase space variables,
describing the particle moving in a central potential in the
-space-time. Using this, we find the modified equations of motion and
show that there is an additional force along the radial direction. Using
Pioneer anomaly data, we set a bond as well as fix the sign of . We also
analyse the violation of equivalence principle predicted by the modified
Newton's equation, valid up to first order in and use this also to set an
upper bound on .Comment: 8 pages, Minor changes in subsection III A made for clarity, to
appear in Mod. Phys. Lett.
On the equivalence between topologically and non-topologically massive abelian gauge theories
We analyse the equivalence between topologically massive gauge theory (TMGT)
and different formulations of non-topologically massive gauge theories (NTMGTs)
in the canonical approach. The different NTMGTs studied are St\"uckelberg
formulation of (A) a first order formulation involving one and two form fields,
(B) Proca theory, and (C) massive Kalb-Ramond theory. We first quantise these
reducible gauge systems by using the phase space extension procedure and using
it, identify the phase space variables of NTMGTs which are equivalent to the
canonical variables of TMGT and show that under this the Hamiltonian also get
mapped. Interestingly it is found that the different NTMGTs are equivalent to
different formulations of TMGTs which differ only by a total divergence term.
We also provide covariant mappings between the fields in TMGT to NTMGTs at the
level of correlation function.Comment: One reference added and a typos corrected. 15 pages, To appear in
Mod. Phys. Lett.
Duality of massive gauge invariant theories in arbitrary space-time dimension
We show that dualization of Stueckelberg-like massive gauge theories and
models, follows form a general p-dualization of interacting
theories in d spacetime dimensions. This is achieved by a particular choice of
the external current.Comment: ReVTeX 7pages, no figures, accepted for publ. in Phys.Rev.
Dual Linearised Gravity in Arbitrary Dimensions
We construct dual formulation of linearised gravity in first order tetrad
formalism in arbitrary dimensions within the path integral framework following
the standard duality algorithm making use of the global shift symmetry of the
tetrad field. The dual partition function is in terms of the (mixed symmetric)
tensor field in {\it frame-like}
formulation. We obtain in d-dimensions the dual Lagrangian in a closed form in
terms of field strength of the dual frame-like field. Next by coupling a source
with the (linear) Riemann tensor in d-dimensions, dual generating functional is
obtained. Using this an operator mapping between (linear) Riemann tensor and
Riemann tensor corresponding to the dual field is derived and we also discuss
the exchange of equations of motion and Bianchi identity.Comment: 14 pages, typos corrected, Published version: Class. Quantum Grav.
22(2005)538
Massive Gauge Axion Fields
A gauge invariant formulation for the massive axion is considered. The axion
acquires mass through a topological term which couples a (pseudo)scalar and a
third rank antisymmetric tensor. Duality, local and canonical equivalences with
the non-gauge invariant proposal are established. The supersymmetric version of
the gauge invariant model is constructed.Comment: Final version. New references adde
A projective Dirac operator on CP^2 within fuzzy geometry
We propose an ansatz for the commutative canonical spin_c Dirac operator on
CP^2 in a global geometric approach using the right invariant (left action-)
induced vector fields from SU(3). This ansatz is suitable for noncommutative
generalisation within the framework of fuzzy geometry. Along the way we
identify the physical spinors and construct the canonical spin_c bundle in this
formulation. The chirality operator is also given in two equivalent forms.
Finally, using representation theory we obtain the eigenspinors and calculate
the full spectrum. We use an argument from the fuzzy complex projective space
CP^2_F based on the fuzzy analogue of the unprojected spin_c bundle to show
that our commutative projected spin_c bundle has the correct
SU(3)-representation content.Comment: reduced to 27 pages, minor corrections, minor improvements, typos
correcte
'Schwinger Model' on the Fuzzy Sphere
In this paper, we construct a model of spinor fields interacting with
specific gauge fields on fuzzy sphere and analyze the chiral symmetry of this
'Schwinger model'. In constructing the theory of gauge fields interacting with
spinors on fuzzy sphere, we take the approach that the Dirac operator on
q-deformed fuzzy sphere is the gauged Dirac operator on fuzzy
sphere. This introduces interaction between spinors and specific one parameter
family of gauge fields. We also show how to express the field strength for this
gauge field in terms of the Dirac operators and alone. Using the path
integral method, we have calculated the point functions of this model and
show that, in general, they do not vanish, reflecting the chiral non-invariance
of the partition function.Comment: Minor changes, typos corrected, 18 pages, to appear in Mod. Phys.
Lett.
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