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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
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Journal ArticleDOI
TL;DR: In this paper, the authors show that the properties of X-ray flash XRF 020903 are consistent with the relation between the fluences S(7-30 keV) and S(30-400 keV), found by Barraud et al. for GRBs.
Abstract: We report High Energy Transient Explorer 2 (HETE-2) Wide Field X-Ray Monitor/French Gamma Telescope observations of the X-ray flash XRF 020903. This event was extremely soft: the ratio log(SX/Sγ) = 0.7, where SX and Sγ are the fluences in the 2-30 and 30-400 keV energy bands, is the most extreme value observed so far by HETE-2. In addition, the spectrum has an observed peak energy of E < 5.0 keV (99.7% probability upper limit), and no photons were detected above ~10 keV. The burst is shorter at higher energies, which is similar to the behavior of long gamma-ray bursts (GRBs). We consider the possibility that the burst lies at very high redshift and that the low value of E is due to the cosmological redshift, and show that this is very unlikely. We find that the properties of XRF 020903 are consistent with the relation between the fluences S(7-30 keV) and S(30-400 keV), found by Barraud et al. for GRBs and X-ray-rich GRBs, and are consistent with the extension by a decade of the hardness-intensity correlation found by the same authors. Assuming that XRF 020903 lies at a redshift z = 0.25, as implied by the host galaxy of the candidate optical and radio afterglows of this burst, we find that the properties of XRF 020903 are consistent with an extension by a factor ~300 of the relation between the isotropic-equivalent energy Eiso and the peak Epeak of the νFν spectrum (in the source frame of the burst) found by Amati et al. for GRBs. The results presented in this paper therefore provide evidence that X-ray flashes (XRFs), X-ray-rich GRBs, and GRBs form a continuum and are a single phenomenon. The results also impose strong constraints on models of XRFs and X-ray-rich GRBs.

134 citations

Journal ArticleDOI
TL;DR: It is shown that the Hamiltonian of the 1D Hubbard model commutes with a one-parameter family of transfer matrices of a new 2D classical model corresponding to two coupled six-vertex models, a generalization of the (infinitesimal) startriangle relation.
Abstract: We show that the Hamiltonian of the 1D Hubbard model commutes with a one-parameter family of transfer matrices of a new 2D classical model corresponding to two coupled six-vertex models. Central to this result is a new local algebraic relation, a generalization of the (infinitesimal) startriangle relation.

134 citations

Journal ArticleDOI
TL;DR: The particle size, fiber density, surface area and pore volume of KCC-1 can be effectively controlled and tuned by changing various reaction parameters, such as the concentrations of urea, CTAB, 1-pentanol, reaction time, temperature, solvent ratio, and even outside stirring time.
Abstract: We report a facile protocol for the synthesis of fibrous nano-silica (KCC-1) with controllable size and fiber density. In this work, we have shown that the particle size, fiber density, surface area and pore volume of KCC-1 can be effectively controlled and tuned by changing various reaction parameters, such as the concentrations of urea, CTAB, 1-pentanol, reaction time, temperature, solvent ratio and even outside stirring time. For the first time, we were able to control the particle size ranging from as small as 170 nm to as large as 1120 nm. We were also able to control the fiber density from low to medium to very dense, which consequently allowed the tuning of the pore volume. We were able to achieve a pore volume of 2.18 cm3/g, which is the highest reported for such a fibrous material. Notably we were even able to increase the surface area up to 1244 m2/g, nearly double the previously reported surface area of KCC-1. Thus, one can now synthesize KCC-1 with various degrees of size, surface area, pore volume and fiber density.

134 citations

Journal ArticleDOI
TL;DR: In this paper, the authors show that a relatively small number of trials in the inner step can yield accurate estimates, and they analyze how a fixed computational budget may be allocated to the inner and the outer step to minimize the mean square error of the resultant estimator.
Abstract: Risk measurement for derivative portfolios almost invariably calls for nested simulation. In the outer step, one draws realizations of all risk factors up to the horizon, and in the inner step, one reprices each instrument in the portfolio at the horizon conditional on the drawn risk factors. Practitioners may perceive the computational burden of such nested schemes to be unacceptable and adopt a variety of second-best pricing techniques to avoid the inner simulation. In this paper, we question whether such short cuts are necessary. We show that a relatively small number of trials in the inner step can yield accurate estimates, and we analyze how a fixed computational budget may be allocated to the inner and the outer step to minimize the mean square error of the resultant estimator. Finally, we introduce a jackknife procedure for bias reduction.

134 citations

Journal ArticleDOI
A. Garmash1, Kazuo Abe, Hiroaki Aihara2, M. Akatsu3  +171 moreInstitutions (42)
TL;DR: In this article, the authors report results on the Dalitz analysis of three-body charmless B+ -> K+ pi(+) pi(-) pi(+)-decays based on a 140 fb(-1) data sample collected with the Belle detector.
Abstract: We report results on the Dalitz analysis of three-body charmless B+ -> K+ pi(+) pi(-) and B+-> K+ K+ K- decays based on a 140 fb(-1) data sample collected with the Belle detector. Measurements of branching fractions for quasi-two-body decays to scalar-pseudoscalar states: B+ -> f(0)(980)K+, B+ -> K-0(*)(1430)(0)pi(+), and to vector-pseudoscalar states: B+ -> K-*(892)(0)pi(+), B+ -> rho(0)K(+), B+ -> phi K+ are presented. Upper limits on decays to some pseudoscalar-tensor final states are reported. We also report the measurement of the B+ -> chi(c0)K(+) branching fraction in two chi(c0) decays channels: chi(c0) -> pi(+)pi(-) and chi(c0) -> K+K-.

134 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
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202322
2022128
2021939
20201,085
20191,100
20181,040