Large D gravity and charged membrane dynamics with nonzero cosmological constant

In this paper, we have found a class of dynamical charged 'black-hole' solutions to Einstein-Maxwell system with a non-zero cosmological constant in a large number of spacetime dimensions. We have solved up to the first sub-leading order using large D scheme where the inverse of the number of dimensions serves as the perturbation parameter. The system is dual to a dynamical membrane with a charge and a velocity field, living on it. The dual membrane has to be embedded in a background geometry that itself, satisfies the pure gravity equation in presence of a cosmological constant. Pure AdS / dS are particular examples of such background. We have also obtained the membrane equations governing the dynamics of the charged membrane. The consistency of our membrane equations is checked by calculating the quasi-normal modes with different Einstein-Maxwell systems in AdS/dS.Comment: 63 pages, v3: appendix added, Accepted for publication in JHE

Spatio-temporal dynamics of vegetable crop production in India

Horticulture is a profitable and diversified option for the development of rural economy. Being endowed with its wide variable climate and soil, India has immense potentialities for the development of horticulture especially vegetable crops production. In the year 2009-10, India is the second largest producer of vegetables in the world (next to China). The present paper highlights the spatio-temporal variations in vegetable production in India by using the secondary data procured from various government websites and offices. The study reveals that in spite of phenomenal growth in vegetable crop production there is lack of any effective policy measures for wiping out the problems relating to low crop productivity, limited irrigational facilities and inadequate infrastructural set up. The existing policies failed to pave the way for sustainable horticulture practice in India

Hydrodynamics, Stability and Accretion: from planets, to stars, to supermassive black holes

In this golden era of multi-messenger astronomy, with highly sensitive telescopes detecting spectacular transients almost nightly, a whole new window is now wide open to study the universe on all timescales. Typically, these events are generated from the total or partial destruction of an astrophysical object and emit electromagnetic waves of all different wavelengths, neutrinos and gravitational waves--carrying important physics that was previously inaccessible. Therefore, it is of utmost importance to take advantage of this tremendous progress in observation with analytic and simulation tools to explain the physics of exotic astrophysical events. This thesis aims to do so by studying the hydrodynamics of some of the most exotic high-energy astrophysical phenomena, ranging from tidal disruption events, shock physics, accretion, and gravitational wave emission from core collapse supernovae, and dynamic stability of the giant planetary atmosphere. We have developed novel analytical tools, primarily using classical hydrodynamics and general relativity, and have utilized computational techniques (numerical and simulations). Our study on giant planets shows how the presence of a solid core can save the planet from being unstable when due to ionization it is expected to be, and thus solves a puzzle in the ``core-accretion” theory of giant planet formation. We have presented a general relativistic modification for the accretion solution on a neutron star through stalled shock, which is useful in understanding weak or failed supernovae and can potentially impact the much-discussed standing accretion shock instability--which we restudied and in the process uncovered a new variant impacting the explosion mechanism and gravitational-wave signature. We have also studied the oscillation modes of a nascent proto-neutron star to show how they can contribute to the gravitational wave signature emitted. Our study of deep-tidal disruption events (events in which stars approach black holes closely) refutes the widely speculated possibility of nuclear detonation arising in such events

Brickwall in Rotating BTZ: A Dip-Ramp-Plateau Story

In this article, building on our recent investigations and motivated by the fuzzball-paradigm, we explore normal modes of a probe massless scalar field in the rotating BTZ-geometry in an asymptotically AdS spacetime and correspondingly obtain the Spectral Form Factor (SFF) of the scalar field. In particular, we analyze the SFF obtained from the single-particle partition function. We observe that, a non-trivial Dip-Ramp-Plateau structure, with a Ramp of slope one (within numerical precision) exists in the SFF which is obtained from the grand-canonical partition function. This behaviour is observed to remain stable close to extremality as well. However, at exact extremality, we observe a loss of the DRP-structure in the corresponding SFF. Technically, we have used two methods to obtain our results: (i) An explicit and direct numerical solution of the boundary conditions to obtain the normal modes, (ii) A WKB-approximation, which yields analytic, semi-analytic and efficient numerical solutions for the modes in various regimes. We further re-visit the non-rotating case and elucidate the effectiveness of the WKB-approximation in this case, which allows for an analytic expression of the normal modes in the regime where a level-repulsion exists. This regime corresponds to the lower end of the spectrum as a function of the scalar angular momentum. By analyzing the classical stress-tensor of the probe sector, we further demonstrate that the back-reaction of the scalar field grows fast as the angular momenta of the scalar modes increase in the large angular momenta regime, while the back-reaction remains controllably small in the regime where the spectrum has non-trivial level correlations. This further justifies cutting the spectrum off at a suitable value of the scalar angular momenta, beyond which the scalar back-reaction significantly modifies the background geometry

Metabolic changes during hibernating period in Indian common toad, Duttaphrynus melanostictus (Schneider, 1799)

The present investigation reports the effect of hibernation on different blood-plasma biochemical parameters viz. plasma protein, plasma glucose and blood urea, thyroid hormone and cholesterol in the Indian Common toad (Duttaphrynus melanostictus). The study indicated that the total plasma protein is decreased significantly in hibernating toads. The decline in thyroid hormone concentration had its behavioral and physiological response that leads to increase and sustain cholesterol level in serum. But plasma glucose was significantly decreased in hibernating toads. During the hibernating phase increased urea concentration in blood acts as cryoprotectant agent, which helps the hibernating animals to sustain in winter. Thus during hibernation these altered metabolic changes appear to be essential for survival

HMN: Generalization of Heterogeneous and Multi-layered Network

A network may have different types of entities and their relations. Further, there could be additional layers of ties. The former is referred to as Heterogeneous networks, while the latter is known as Multi-layer networks. The present paper provides a generalized network model, namely, a Heterogeneous Multi-layered Network (HMN), which can simultaneously be multi-layered and heterogeneous. The model can represent homogeneous networks as well. We define different structural measures in an HMN. We proved that the sets of all homogeneous, heterogeneous and multi-layered networks are subsets of the set of all HMNs. Accordingly, we established the equivalency of the proposed structural measures of HMNs with that of homogeneous, heterogeneous, and multi-layered networks. Following that, we show how our proposed HMN is more efficient in tasks such as link prediction. In addition, we present a novel parameterized algorithm (with complexity analysis) for generating synthetic HMNs. The networks generated from our proposed algorithm are more consistent in modelling the layer-wise degree distribution of a real-world Twitter network (represented as HMN) than those generated by existing models. Moreover, we also show that our algorithm is more effective in modelling an air-transportation multiplex network when compared to an algorithm designed specifically for the task

An Empirical Analysis of Women Empowerment within Muslim Community in Murshidabad District of West Bengal, India

Women empowerment is a contemporary issue for developing countries like India. The rates of women empowerment are in a vulnerable condition within the largest Muslim minority community of India. In this paper, an attempt has been taken to present an empirical analysis of Muslim women empowerment within purposively selected Murshidabad district of West Bengal regarding the highest concentration of Muslim people (63.67%) all over the country. For showing the multidimensional aspects of women empowerment, a Cumulative Empowerment Index (CEI) has been constructed using 22 key indicators that act as explained variables covering four dimension of women empowerment, i.e. control over economic resources, control over household decision making, women’s mobility and political awareness. Nine explanatory (independent) variables have also been selected as determinants of women empowerment (CEI). Based on the multiple regression results the study finds statistically significant impact of accessing any type of media, family structure, family headship, household income, paid work and duration of marital life on Cumulative Empowerment Index of Muslim women at the study area. It concludes that active participation of GO’s and local NGO’s in bringing change of traditional beliefs of Muslim family and gaining awareness about women’s rights and practices can accelerate the women empowerment process within Muslim community of Murshidabad district. Keywords: Women empowerment, Cumulative Empowerment Index, Muslim community, Multiple regressio

A CLINICAL STUDY ON GUDUCHI SATTAVA (STARCH OBTAIN FROM STEM OF TINOSPORA CORDIFOLIA) IN MADHUMEHA W.S.R. TO DIABETES MELLITUS TYPE II

Madhumeha (Type 2 Diabetes Mellitus) is a global burden. At present, it occupies significant position among non-communicable diseases. It is a major cause of mortality and morbidity in middle age group people. Alterations in metabolism have been main culprit in the pathology of Type 2 Diabetes Mellitus. There are several challenges in diabetes management, including a rising prevalence in urban and rural areas, lack of disease awareness among the public, limited health care facilities, high cost of treatment, suboptimal glycemic control and rising prevalence of diabetic complications. India has to take drastic and urgent steps to develop an integrated national system for early detection and prevention and better management of Diabetes Mellitus. The present clinical study conducted to evaluate the effectiveness of Guduchi sattava in reliving the symptoms of hyperglycemia. Fifty newly diagnosed Madhumeha patients of either sex in the age group of 30-70 years are included in this study. Guduchi sattava (1g daily) are given orally for 90 days with plan water with and without diet restriction and exercise. Type 1Diabetes Mellitus, Diabetes Mellitus with pregnancy, Gestational diabetes etc are excluded here. All patients are evaluated based on clinical features, and laboratory parameters like-blood glucose level, lipid profile and HbA1C. The present study concluded that Guduchi sattava has definite hypoglycemic effect and more effective on fasting glucose level then postprandial glucose along with diet and exercise