5,367 research outputs found
The role of field redefinition on renormalisability of a general supersymmetric gauge theories
We investigate some issues on renormalisability of non-anticommutative
supersymmetric gauge theory related to field redefinitions. We study one loop
corrections to supersymmetric gauge theory
coupled to chiral matter in component formalism, and show the procedure which
has been introduced for renormalisation is problematic because some terms which
are needed for the renormalisability of theory are missed from the Lagrangian.
In order to prove the theory is renormalisable, we redefine the gaugino and the
auxiliary fields(), which result in a modified form of the
Lagrangian in the component formalism. Then, we show the modified Lagrangian
has extra terms which are necessary for renormalisability of
non-anticommutative supersymmetric gauge field theories. Finally we prove supersymmetric gauge theory is renormalisable up to one loop
corrections using standard method of renormalisation; besides, it is shown the
effective action is gauge invariant.Comment: arXiv admin note: text overlap with arXiv:hep-th/0505248 by other
author
Quantum gravitational optics in the field of a gravitomagnetic monopole
Vacuum polarization in QED in a background gravitational field induces
interactions which {\it effectively} modify the classical picture of light rays
as the null geodesics of spacetime. After a short introduction on the main
aspects of the quantum gravitational optics, as a nontrivial example, we study
this effect in the background of NUT space characterizing the spacetime of a
spherical mass endowed with a gravitomagnetic monopole charge, the so called
NUT factor.Comment: 9 pages, title changed and the text abridged for publication in the
Journal of Physics: Conference serie
Transverse expansion of hot magnetized Bjorken flow in heavy ion collisions
We argue that the existence of an inhomogeneous external magnetic field can
lead to radial flow in transverse plane. Our aim is to show how the
introduction of a magnetic field generalizes the Bjorken flow. We investigate
the effect of an inhomogeneous weak external magnetic field on the transverse
expansion of in-viscid fluid created in high energy nuclear collisions. In
order to simplify our calculation and compare with Gubser model, we consider
the fluid under investigation to be produced in central collisions, at small
impact parameter; azimuthal symmetry has been considered. In our model, we
assume an inhomogeneous external magnetic field following the power-law decay
in proper time and having radial inhomogeneity perpendicular to the radial
velocity of the in-viscid fluid in the transverse plane; then the space time
evolution of the transverse expansion of the fluid is obtained. We also show
how the existence of an inhomogeneous external magnetic field modifies the
energy density. Finally we use the solutions for the transverse velocity and
energy density in the presence of a weak magnetic field, to estimate the
transverse momentum spectrum of protons and pions emerging from the
Magneto-hydrodynamic solutions
New bounds on the signed total domination number of graphs
In this paper, we study the signed total domination number in graphs and
present new sharp lower and upper bounds for this parameter. For example by
making use of the classic theorem of Turan, we present a sharp lower bound on
this parameter for graphs with no complete graph of order r+1 as a subgraph.
Also, we prove that n-2(s-s') is an upper bound on the signed total domination
number of any tree of order n with s support vertices and s' support vertives
of degree two. Moreover, we characterize all trees attainig this bound.Comment: This paper contains 11 pages and one figur
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