Static potential in scalar QED3_3 with non-minimal coupling

Here we compute the static potential in scalar $QED_3$ at leading order in $1/N_f$. We show that the addition of a non-minimal coupling of Pauli-type (\eps j^{\mu}\partial^{\nu}A^{\alpha}), although it breaks parity, it does not change the analytic structure of the photon propagator and consequently the static potential remains logarithmic (confining) at large distances. The non-minimal coupling modifies the potential, however, at small charge separations giving rise to a repulsive force of short range between opposite sign charges, which is relevant for the existence of bound states. This effect is in agreement with a previous calculation based on M$\ddot{o}$ller scattering, but differently from such calculation we show here that the repulsion appears independently of the presence of a tree level Chern-Simons term which rather affects the large distance behavior of the potential turning it into constant.Comment: 13 pages, 3 figure

Cloud of strings for radiating black holes in Lovelock gravity

We present exact spherically symmetric null dust solutions in the third order Lovelock gravity with a string cloud background in arbitrary $N$ dimensions,. This represents radiating black holes and generalizes the well known Vaidya solution to Lovelock gravity with a string cloud in the background. We also discuss the energy conditions and horizon structures, and explicitly bring out the effect of the string clouds on the horizon structure of black hole solutions for the higher dimensional general relativity and Einstein-Gauss-Bonnet theories. It turns out that the presence of the coupling constant of the Gauss-Bonnet terms and/or background string clouds completely changes the structure of the horizon and this may lead to a naked singularity. We recover known spherically symmetric radiating models as well as static black holes in the appropriate limits.Comment: 9 pages, To appear in Phys. Rev.

Discrete optimization problems with random cost elements

In a general class of discrete optimization problems, some of the elements mayhave random costs associated with them. In such a situation, the notion of optimalityneeds to be suitably modified. In this work we define an optimal solutionto be a feasible solution with the minimum risk. We focus on the minsumobjective function, for which we prove that knowledge of the mean values ofthese random costs is enough to reduce the problem into one with fixed costs.We discuss the implications of using sample means when the true means ofthe costs of the random elements are not known, and explore the relation betweenour results and those from post-optimality analysis. We also show thatdiscrete optimization problems with min-max objective functions depend moreintricately on the distributions of the random costs.

Complete local search with memory

Neighborhood search heuristics like local search and its variants are some of the most popular approaches to solve discrete optimization problems of moderate to large size. Apart from tabu search, most of these heuristics are memoryless. In this paper we introduce a new neighborhood search heuristic that makes effctive use of memory structures in a way that is different from tabu search. We report computational experiments with this heuristic on the traveling salesperson problem and the subset sum problem.

Off-balance sheet activities in banking: Theory and Indian experience

The paper examines the OBS activities of Indian banks, highlighting, in particular, thier growth, diversification and the factors leading to thier increased usageoff-balance sheet; banking; India

An empirical analysis of the off-balance sheet activities of Indian banks

The paper traces the determinants of off-balance sheet activities in the Indian banking sector. Using data for the period 1996 to 2004, the paper finds that, not only regulatory factors, but also market forces, captured by banks-specific characteristics and macroeconomic conditions are at work in the diffusion pattern of OBS activities. From the regulatory standpoint, while capital adequacy is dominant in case of public sector banks, non-performing assets seem to a prime concern for foreign banks, in addition to the public sector banks. Among others, at the bank-specific level, size is an important consideration for public sector and foreign banks, while profits are a prime mover only for new private banks. Finally, the macroeconomic environment seems to have played an important role in affecting OBS diffusion, more so for public sector and new private banks.Off-balance sheet; regulatory pressure; interest spread; banking; India