arXiv subjects

Kuldeep Kumar

Publications and source records attributed to Kuldeep Kumar.

25 records · Page 2Linked to original sources

arXiv2007

Alternative Method for Studying Color Centers in CsCl Thin Films

The optical properties of cesium chloride (CsCl) are changed with presence of vacancies in the crystal structure giving rise to what is called as "color centers". We have unconventionally adopted Tauc's method to determine the characteristic color centers and have modeled the correlation among the film optical properties and lattice size, highlighting the interrelation between the structural and optical properties of alkali halide films.

cond-mat.mtrl-sci↗

arXiv2007

Deformed relativistic and nonrelativistic symmetries on canonical noncommutative spaces

We study the general deformed conformal-Poincare (Galilean) symmetries consistent with relativistic (nonrelativistic) canonical noncommutative spaces. In either case we obtain deformed generators, containing arbitrary free parameters, which close to yield new algebraic structures. We show that a particular choice of these parameters reproduces the undeformed algebra. The modified coproduct rules and the associated Hopf algebra are also obtained. Finally, we show that for the choice of parameters leading to the undeformed algebra, the deformations are represented by twist functions.

hep-th↗

arXiv2005

Seiberg-Witten maps and commutator anomalies in noncommutative electrodynamics

We exploit the Seiberg-Witten maps for fields and currents in a U(1) gauge theory relating the noncommutative and commutative (usual) descriptions to obtain the O(θ) structure of the commutator anomalies in noncommutative electrodynamics. These commutators involve the (covariant) current-current algebra and the (covariant) current-field algebra. We also establish the compatibility of the anomalous commutators with the noncommutative covariant anomaly through the use of certain consistency conditions derived here.

hep-th↗

arXiv2005

Conditional probability of actually detecting a financial fraud - a neutrosophic extension to Benford's law

This study actually draws from and builds on an earlier paper (Kumar and Bhattacharya, 2002). Here we have basically added a neutrosophic dimension to the problem of determining the conditional probability that a financial fraud has been actually committed, given that no Type I error occurred while rejecting the null hypothesis H0: The observed first-digit frequencies approximate a Benford distribution; and accepting the alternative hypothesis H1: The observed first-digit frequencies do not approximate a Benford distribution. We have also suggested a conceptual model to implement such a neutrosophic fraud detection system.

math.GM↗

arXiv2005

Maps for currents and anomalies in noncommutative gauge theories

We derive maps relating currents and their divergences in non-abelian U(N) noncommutative gauge theory with the corresponding expressions in the ordinary (commutative) description. For the U(1) theory, in the slowly-varying-field approximation, these maps are also seen to connect the star-gauge-covariant anomaly in the noncommutative theory with the standard Adler--Bell--Jackiw anomaly in the commutative version. For arbitrary fields, derivative corrections to the maps are explicitly computed up to O(θ^2).

hep-th↗

arXiv2004

Noncommutative gauge theories and Lorentz symmetry

We explicitly derive, following a Noether-like approach, the criteria for preserving Poincare invariance in noncommutative gauge theories. Using these criteria we discuss the various spacetime symmetries in such theories. It is shown that, interpreted appropriately, Poincare invariance holds. The analysis is performed in both the commutative as well as noncommutative descriptions and a compatibility between the two is also established.

hep-th↗

arXiv2003

Membrane and Noncommutativity

We analyse the dynamics of an open membrane, both for the free case and when it is coupled to a background three-form, whose boundary is attached to $p$-branes. The role of boundary conditions and constraints in the Nambu-Goto and Polyakov formulations is studied. The low-energy approximation that effectively reduces the membrane to an open string is examined in detail. Noncommutative features of the boundary string coordinates, where the cylindrical membrane is attached to the D$p$-branes, are revealed by algebraic consistency arguments and not by treating boundary conditions as primary constraints, as is usually done. The exact form of the noncommutative algebra is obtained in the low-energy limit.

hep-th↗