scispace - formally typeset
Search or ask a question
Institution

Tata Institute of Fundamental Research

EducationMumbai, Maharashtra, India
About: Tata Institute of Fundamental Research is a education organization based out in Mumbai, Maharashtra, India. It is known for research contribution in the topics: Magnetization & Large Hadron Collider. The organization has 7786 authors who have published 21742 publications receiving 622368 citations. The organization is also known as: TIFR.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, the authors analyse the dynamics of near-extremal Reissner-Nordstrom black holes in asymptotically four-dimensional Anti de Sitter space (AdS4) and study the thermodynamics and the response to a probe scalar field.
Abstract: We analyse the dynamics of near-extremal Reissner-Nordstrom black holes in asymptotically four-dimensional Anti de Sitter space (AdS4). We work in the spherically symmetric approximation and study the thermodynamics and the response to a probe scalar field. We find that the behaviour of the system, at low energies and to leading order in our approximations, is well described by the Jackiw-Teitelboim (JT) model of gravity. In fact, this behaviour can be understood from symmetry considerations and arises due to the breaking of time reparametrisation invariance. The JT model has been analysed in considerable detail recently and related to the behaviour of the SYK model. Our results indicate that features in these models which arise from symmetry considerations alone are more general and present quite universally in near-extremal black holes.

174 citations

Journal ArticleDOI
TL;DR: Theorem 6.5.1 as mentioned in this paper shows that if V is semistable on a nonsingular projective variety of dimension n over an algebraically closed field k, then its restriction to a general complete intersection curve of sufficiently high degree is also semistability.
Abstract: Let X be a nonsingular projective variety of dimension n over an algebraically closed field k. Let H be a very ample line bundle on X. If V is a torsion free coherent sheaf on X we define deg V to be cl(V), c~(H)"~ and/~(V) = deg V/rk V. We call V sernistable (resp. stable) if for all proper subsheaves W of V we have #(W) < #(V) [resp. #(W) < #(V)] (cf. [7, 14]). In this paper we prove that if V is semistable on X then its restriction to a general complete intersection curve of sufficiently high degree is semistable (Theorem 6.1). To give an idea of the proof assume X is a surface and V a vector bundle of rank 2. The restriction of V to a general curve C" of degree m is not semistable if and only if it is not semistable on the generic curve Ym defined over the function field of IPH~ H"). Let/S," be the line bundle on Y,, contradicting the semistability of VI Y,, (cf. Sects. 4.1 and 4.2). First we show that L,, extends uniquely to a line bundle L m on X (Proposition 2.1). If we can get L" as a subbundle of V we are through, for then L" would contradict the semistability of V. So we would like the restriction map H~ Hom(Lm, V))~H~ Hom(L m, V)) to be surjective. Now for fixed L it follows from the lemma of Enriques-Severi (Proposition 3.2; [6, Corollary 7.8]) that H~ Horn(L, V))~H~ Horn(L, V)) is surjective for large m. Therefore it is enough if the L" remain the same line bundle L for infinitely many m. To prove that L,, = L we construct a degenerating family of curves D f ~S, X x S 3 D p ~X, such that the generic fibre is a curve Ct"+ 1) of degree 2 "+ 1 and the special fibre is a reduced curve with two nonsingular components CI") of degree 2" (cf. Sect. 5). Let (m) denote 2". Extending the subbundle Lt,,+~)[Ct"+~) to a subsheaf of p*(V) on D and restricting the extension to CI") gives a lower bound for the maximal degree of a line subbundle of V[CIm ) in terms of that for V[Ctm+I ) (Proposition 4.3). This implies that degL,, is bounded (Lemma 6.5.1) so that for an infinite subsequence of m, degL,, is constant. If degLtm + r)= degLt,,) by refining the above argument with the degenerating family one can prove that Lt"+,)[ CI")

174 citations

Journal ArticleDOI
TL;DR: A novel magneto-optical phenomenon that originates solely from suitably designed nanostructured metal-dielectric material, the so-called Magneto-plasmonic crystal, which allows manipulating and exciting waveguide modes by a magnetic field and light of proper polarization.
Abstract: Magnetic field control of light is among the most intriguing methods for modulation of light intensity and polarization on sub-nanosecond timescales. The implementation in nanostructured hybrid materials provides a remarkable increase of magneto-optical effects. However, so far only the enhancement of already known effects has been demonstrated in such materials. Here we postulate a novel magneto-optical phenomenon that originates solely from suitably designed nanostructured metal-dielectric material, the so-called magneto-plasmonic crystal. In this material, an incident light excites coupled plasmonic oscillations and a waveguide mode. An in-plane magnetic field allows excitation of an orthogonally polarized waveguide mode that modifies optical spectrum of the magneto-plasmonic crystal and increases its transparency. The experimentally achieved light intensity modulation reaches 24%. As the effect can potentially exceed 100%, it may have great importance for applied nanophotonics. Further, the effect allows manipulating and exciting waveguide modes by a magnetic field and light of proper polarization.

174 citations

Journal ArticleDOI
TL;DR: Results of experiments with mammalian cells and zebra fish show that RR1 is cell and organism permeable and that it responds selectively to mercury ions over other metal ions, and real-time monitoring of inorganic mercury ion uptake by cells and live zebrafish using this chemosensor shows that saturation of mercury ions uptake occurs within 20-30 min in cells and organisms.
Abstract: We introduce a new rhodamine–rhodanine-based “turn-on” fluorescent sensor (RR1) and describe its application for detection of mercury, including in solution, in live cells, and in a living vertebrate organism. The sensor RR1, which is a one-pot synthesis from rhodamine B, undergoes a rapid and irreversible 1:1 stoichiometric reaction with Hg2+ in aqueous medium. Using fluorescence correlation spectroscopy (FCS), RR1 was shown to detect the presence of as low as a 0.5 pM concentration of Hg2+. It may also lend itself to tagging with biomolecules and nanoparticles, leading to the possibility of organelle-specific Hg detection. Results of experiments with mammalian cells and zebrafish show that RR1 is cell and organism permeable and that it responds selectively to mercury ions over other metal ions. In addition, real-time monitoring of inorganic mercury ion uptake by cells and live zebrafish using this chemosensor shows that saturation of mercury ion uptake occurs within 20–30 min in cells and organisms. We ...

174 citations

Journal ArticleDOI
TL;DR: The Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) as mentioned in this paper was designed with the primary aim of detecting galaxy clusters at z > 1, using an infrared adaptation of the two-filter red-sequence cluster technique.
Abstract: The Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) is a z ′ -passband imaging survey, consisting of deep (z ′ ≃ 24 AB) observations made from both hemispheres using the CFHT 3.6m and CTIO 4m telescopes. The survey was designed with the primary aim of detecting galaxy clusters at z > 1. In tandem with pre-existing 3.6µm observations from the Spitzer Space Telescope SWIRE Legacy Survey, SpARCS detects clusters using an infrared adaptation of the two-filter redsequence cluster technique. The total effective area of the SpARCS cluster survey is 41.9 deg 2 . In this paper, we provide an overview of the 13.6 deg 2 Southern CTIO/MOSAICII observations. The 28.3 deg 2 Northern CFHT/MegaCam observations are summarized in a companion paper by Muzzin et al. (2008a). In this paper, we also report spectroscopic confirmation of SpARCS J003550431224, a very rich galaxy cluster at z = 1.335, discovered in the ELAIS-S1 field. To date, this is the highest spectroscopically confirmed redshift for a galaxy cluster discovered using the red-sequence technique. Based on nine confirmed members, SpARCS J003550-431224 has a preliminary velocity dispersion of 1050 ±230 km s −1 . With its proven capability for efficient cluster detection,SpARCS is a demonstration that we have entered an era of large, homogeneously-selected z > 1 cluster surveys. Subject headings: surveys — cosmology: observations — galaxies: clusters: general — galaxies: highredshift — infrared: galaxies

174 citations


Authors

Showing all 7857 results

NameH-indexPapersCitations
Pulickel M. Ajayan1761223136241
Suvadeep Bose154960129071
Subir Sarkar1491542144614
Sw. Banerjee1461906124364
Dipanwita Dutta1431651103866
Ajit Kumar Mohanty141112493062
Tariq Aziz138164696586
Andrew Mehta1371444101810
Suchandra Dutta134126587709
Kajari Mazumdar134129594253
Bobby Samir Acharya1331121100545
Gobinda Majumder133152387732
Eric Conte132120684593
Prashant Shukla131134185287
Alessandro Montanari131138793071
Network Information
Related Institutions (5)
Max Planck Society
406.2K papers, 19.5M citations

90% related

University of Paris-Sud
52.7K papers, 2.1M citations

90% related

Los Alamos National Laboratory
74.6K papers, 2.9M citations

90% related

Brookhaven National Laboratory
39.4K papers, 1.7M citations

89% related

Weizmann Institute of Science
54.5K papers, 3M citations

89% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202322
2022128
2021939
20201,085
20191,100
20181,040