Gravity and Large Extra Dimensions

The idea that quantum gravity can be realized at the TeV scale is extremely attractive to theorists and experimentalists alike. This proposal leads to extra spacial dimensions large compared to the electroweak scale. Here we give a very systematic view of the foundations of the theories with large extra dimensions and their physical consequences.Comment: 26 pages, 3 diagram

Author productivity and the application of Lotka’s Law in LIS publications

The paper examines authorship pattern of 556 papers published in Journal of Documentation during 2003 to 2015. In addition to the papers, a sample of 1550 references from a population of 15,529 unique references given at the end of the papers was selected using simple random sample method. It was found that almost half of the publications were written by single authors. Lotka’s Law was tested on the resulting 2106 publications using Kolmogorov-Smrinov goodness-of-fit. The K-S test and the author productivity graph revealed that Lotka’s law was applicable to the set LIS publications.

Supernovae as Probes of Extra Dimensions

Since the dawn of the new millennium, there has been a revived interest in the concept of extra dimensions.In this scenario all the standard model matter and gauge fields are confined to the 4 dimensions and only gravity can escape to higher dimensions of the universe.This idea can be tested using table-top experiments, collider experiments, astrophysical or cosmological observations. The main astrophysical constraints come from the cooling rate of supernovae, neutron stars, red giants and the sun. In this article, we consider the energy loss mechanism of SN1987A and study the constraints it places on the number and size of extra dimensions and the higher dimensional Planck scale.Comment: 5 pages, no figures, new references are adde

Plasmon Annihilation into Kaluza-Klein Graviton: New Astrophysical Constraints on Large Extra Dimensions

In large extra dimensional Kaluza-Klein (KK) scenario, where the usual Standard Model (SM) matter is confined to a 3+1-dimensional hypersurface called the 3-brane and gravity can propagate to the bulk (D=4+d, d being the number of extra spatial dimensions), the light graviton KK modes can be produced inside the supernova core due to the usual nucleon-nucleon bremstrahlung, electron-positron and photon-photon annihilations. This photon inside the supernova becomes plasmon due to the plasma effect. In this paper, we study the energy-loss rate of SN 1987A due to the KK gravitons produced from the plasmon-plasmon annihilation. We find that the SN 1987A cooling rate leads to the conservative bound $M\_D$ > 22.9 TeV and 1.38 TeV for the case of two and three space-like extra dimensions.Comment: 13 pages, 1 ps figure, text is modified a little bit, conclusion unchanged, new references are added, version accepted for publication in PR

Effect of Sheep Grazing and Rainfall on the Ecology of \u3cem\u3eLasiurus sindicus\u3c/em\u3e-Dominated Grassland in Hot Arid Zone of India

Thar Desert in India is very fragile owing to frequent drought and low rainfall which causes extreme stress on biodiversity of region especially on livestock due to limited seasonal grazing resources. Despite inhospitable and harsh climate, as well as anthropogenic pressures, Indian arid zone has 682 species belonging to 352 genera and 87 families. Some 63 species are introduced belonging to 37 genera and 9 families. Compared to other deserts of the world, this desert has higher number of endemic species, i.e. 6.4%. Poaceae and Leguminosae are the largest species. All these species have typical habitat-plant cover relationship resulting in major vegetation types on hills and rock outcrops, piedmonts and pediments, alluvial plains, saline flats, fresh water lakes/talavs, river and stream banks, sandy hummocky plains and sand dunes of varying shapes and sizes. CAZRI has been actively engaged since inception in assessing the status of natural vegetation, its distribution pattern, utilization trends, economic importance and degradation status at district as well as habitat level. Though fairly good understanding exists on progressive successional trends on major habitats but dynamics of retrogressive trends is poorly understood more so in varying rainfall scenarios. Hence, this study was taken up to understand these trends in respect of Lasiurus sindicus, a key grass species along with other associated species in Jaisalmer, in the extreme arid region of India

Sharptail mola landed at Thoothukudi

A large Sharptail mola (Masturus lanceolatus) measuring 180 cm in Total length (TL) landed on 28.07.2016 at Tharuvaikulam Landing Centre, Gulf of Mannar. Interaction with the local fishermen indicated that it was caught at a depth of 150 m in a drift gill net conducting multiday fishing for 4-5 days about 40 km from shore

Significance of HOMO and LUMO studies on dye doped glycene lithium sulphate (GLS) crystals for non-linear optical applications

The ideal material that could have potential applications in non-linear optical (NLO) devices should possess the combination of large non-linear figure of merit for frequency conversion, high laser damage threshold, fast optical response time, wide phase matchable angle, architectural flexibility for molecular design and morphology, optical transparency and high mechanical strength. The stability of glycene lithium sulphate (GLS) single crystal has been improved by doping organic dyes. The structural, chemical, optical, mechanical and non-linear optical properties of the dye doped crystals have been analyzed with the characterization studies such as powder XRD, FT-IR, UV-Visible and SHG measurements, respectively. NMR, HOMO and LUMO energies have been performed by time dependent density functional theory (TD-DFT) approach. The Mulliken charge analysis indicates that the sulphur atoms of the benzene ring and the OH group attached to the ring are the main reactive centers of glycene lithium sulphate. And the temperature dependence of the thermodynamic properties of constant pressure (Cp), entropy (S) and enthalpy change (ΔH0→T) for glycene lithium sulphate have also been determined