On the production mechanism of radio-pulses from large extensive air showers

None of the theories put forward so far to explain the radio emission from cosmic ray showers, has been successful in giving a satisfactory explanation for all the experimental data obtained from various laboratories over the globe. It is apprehended that emission mechanism at low and high frequencies may be quite different. This calls for new theoretical look into the phenomenon. Theoretical as well as the experimental results indicate that the frequency spectrum is rather flat in the frequency range (40 to 60 MHz. Above 80 MHz, the radio emission can be explained with the help of geomagnetic mechanism. But at very low frequency ( 10 MHz), mechanisms other than geomagnetic are involved

Community at the Core: A Study of Sarvodaya Nano Finance Limited

The paper traces the evolution of Sarvodaya Nano Finance Limited (SNFL). At the outset we explore the background of SNFL, the motivation for the promoters to set up the organisation and how it has grown from the time it was taken over by the community trusts promoted by ASSEFA. As a part of the study, we examine the unique legal structure set up for federating the small SHGs that were widely spread out in the areas of its operation. The idea of federating the SHGs was to leverage the dispersed savings and interest earned on the initial donor resources that were made available to the SHGs at their early stages. The aggregation of these dispersed resources into SNFL enables the women SHGs to mobilise funds from commercial banks and specialised MFI lenders, for an accelerated growth of the movement. The paper examines the rationale for having this structure, its vulnerabilities and the possibilities for growth within the given structure. We argue that this is not a structure that can be replicated easily. We also argue that it cannot grow aggressively in the long run, unless some basic design changes are made. The paper also discusses the basic question on how to structure resources that are given by the donor community for the larger benefit of the poor; and when to bring in the individual stakes of the beneficiaries if one were to promote long lasting institutions. The paper also raises critical questions on governance and management. While appreciating the impressive result achieved by ASSEFA and BASIX in getting a community owned professionally managed institution into being, it also raises questions on whether there are inbuilt mechanisms of carrying forward this effectively in future – given the structuring of capital and rights of each of the constituents.

Dynamics of interacting quintessence

In this paper, we investigate coupled quintessence with scaling potential assuming specific forms of the coupling as $A$ namely, $\alpha \dot{\rho_m}$, $\beta \dot{\rho_{\phi}}$ and $\sigma (\dot{\rho_m}+\dot{\rho_{\phi}})$, and present phase space analysis for three different interacting models. We focus on the attractor solutions that can give rise to late time acceleration with $\Omega_{DE}/\Omega_{DM}$ of order unity in order to alleviate the coincidence problem.Comment: 11 pages, 3 figures, matches with the published versio

Non-destructive Orthonormal State Discrimination

We provide explicit quantum circuits for the non-destructive deterministic discrimination of Bell states in the Hilbert space $C^{d^{n}}$, where $d$ is qudit dimension. We discuss a method for generalizing this to non-destructive measurements on any set of orthogonal states distributed among $n$ parties. From the practical viewpoint, we show that such non-destructive measurements can help lower quantum communication complexity under certain conditions.Comment: 11 pages, 6 fugure

Microprocessor-based single particle calibration of scintillation counter

A microprocessor-base set-up is fabricated and tested for the single particle calibration of the plastic scintillator. The single particle response of the scintillator is digitized by an A/D converter, and a 8085 A based microprocessor stores the pulse heights. The digitized information is printed. Facilities for CRT display and cassette storing and recalling are also made available

Special values of derivatives of LL-series and generalized Stieltjes constants

The connection between derivatives of $L(s,f)$ for periodic arithmetical functions $f$ at $s=1$ and generalized Stieltjes constants has been noted earlier. In this paper, we utilize this link to throw light on the arithmetic nature of $L'(1,f)$ and certain Stieltjes constants. In particular, if $p$ is an odd prime greater than $7$, then we deduce the transcendence of at least $(p-7)/2$ of the generalized Stieltjes constants, $\{ \gamma_1(a,p) : 1 \leq a < p \}$, conditional on a conjecture of S. Gun, M. R. Murty and P. Rath.Comment: 11 page