Institution
Tata Institute of Fundamental Research
Education•Mumbai, 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.
Topics: Magnetization, Large Hadron Collider, Galaxy, Higgs boson, Lepton
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the free energy of SU(N) Chern-Simons theories at level k with both fermionic and bosonic vector matter was discussed and a generalization of the standard Hubbard-Stratanovich method was proposed to handle higher order polynomial interactions.
Abstract: In this paper we discuss SU(N) Chern-Simons theories at level k with both fermionic and bosonic vector matter. In particular we present an exact calculation of the free energy of the N = 2 supersymmetric model (with one chiral field) for all values of the `t Hooft coupling in the large N limit. This is done by using a generalization of the standard Hubbard-Stratanovich method because the SUSY model contains higher order polynomial interactions.
119 citations
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TL;DR: The Cosmic Microwave Background fluctuations provide a powerful probe of the dark ages of the universe through the imprint of the secondary anisotropies associated with the reionization of universe and the growth of structure as discussed by the authors.
Abstract: The Cosmic Microwave Background fluctuations provide a powerful probe of the dark ages of the universe through the imprint of the secondary anisotropies associated with the reionization of the universe and the growth of structure. We review the relation between the secondary anisotropies and the primary anisotropies that are directly generated by quantum fluctuations in the very early universe. The physics of secondary fluctuations is described, with emphasis on the ionization history and the evolution of structure. We discuss the different signatures arising from the secondary effects in terms of their induced temperature fluctuations, polarization and statistics. The secondary anisotropies are being actively pursued at present, and we review the future and current observational status.
119 citations
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TL;DR: In this paper, the authors derived a third-order hydrodynamic evolution equation for the shear stress tensor from kinetic theory and showed that the results obtained using the thirdorder viscous equations derived here provide a very good approximation to the exact solution of the Boltzmann equation in a relaxation time approximation.
Abstract: We present the derivation of a novel third-order hydrodynamic evolution equation for the shear stress tensor from kinetic theory. The Boltzmann equation with a relaxation time approximation for the collision term is solved iteratively using a Chapman-Enskog-like expansion to obtain the nonequilibrium phase-space distribution function. Subsequently, the evolution equation for the shear stress tensor is derived from its kinetic definition up to third order in gradients. We quantify the significance of the new derivation within a one-dimensional scaling expansion and demonstrate that the results obtained using the third-order viscous equations derived here provides a very good approximation to the exact solution of the Boltzmann equation in a relaxation time approximation. We also show that the time evolution of pressure anisotropy obtained using our equations is in better agreement with transport results than that obtained with an existing third-order calculation based on the second law of thermodynamics.
118 citations
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University of Turku1, Jagiellonian University2, Pedagogical University3, Agenzia Spaziale Italiana4, Istituto Nazionale di Fisica Nucleare5, Tata Institute of Fundamental Research6, Osaka Kyoiku University7, European Space Agency8, National and Kapodistrian University of Athens9, Liverpool John Moores University10, Physical Research Laboratory11, Çanakkale Onsekiz Mart University12, Appalachian State University13, National Institute of Astrophysics, Optics and Electronics14, University of Delaware15, Atatürk University16, University of California, Berkeley17, Aryabhatta Research Institute of Observational Sciences18, University of North Carolina at Chapel Hill19, Academy of Sciences of the Czech Republic20, Czech Technical University in Prague21, Tohoku University22, University of Alabama23, Korea University of Science and Technology24, Korea Astronomy and Space Science Institute25, INAF26, University of Helsinki27, Technische Universität München28, Max Planck Society29, University of Colorado Boulder30, Nicolaus Copernicus University in Toruń31, Florida International University32, University of Zielona Góra33, IAC34
TL;DR: In this paper, a quasi-periodic quasar with roughly 12-year optical cycles displays prominent outbursts that are predictable in a binary black hole model, and the model predicted a major optical outburst in 2015 December.
Abstract: OJ 287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts that are predictable in a binary black hole model. The model predicted a major optical outburst in 2015 December. We found that the outburst did occur within the expected time range, peaking on 2015 December 5 at magnitude 12.9 in the optical R-band. Based on Swift/XRT satellite measurements and optical polarization data, we find that it included a major thermal component. Its timing provides an accurate estimate for the spin of the primary black hole, $\chi =0.313\pm 0.01$. The present outburst also confirms the established general relativistic properties of the system such as the loss of orbital energy to gravitational radiation at the 2% accuracy level, and it opens up the possibility of testing the black hole no-hair theorem with 10% accuracy during the present decade.
118 citations
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TL;DR: In this paper, the effects of possible systematic errors in the waveform models on estimates of its source parameters were investigated and no evidence for a systematic bias relative to the statistical error of the original parameter recovery of GW150914 due to modeling approximations or modeling inaccuracies was found.
Abstract: Parameter estimates of GW150914 were obtained using Bayesian inference, based on three semi-analytic waveform models for binary black hole coalescences. These waveform models differ from each other in their treatment of black hole spins, and all three models make some simplifying assumptions, notably to neglect sub-dominant waveform harmonic modes and orbital eccentricity. Furthermore, while the models are calibrated to agree with waveforms obtained by full numerical solutions of Einstein's equations, any such calibration is accurate only to some non-zero tolerance and is limited by the accuracy of the underlying phenomenology, availability, quality, and parameter-space coverage of numerical simulations. This paper complements the original analyses of GW150914 with an investigation of the effects of possible systematic errors in the waveform models on estimates of its source parameters. To test for systematic errors we repeat the original Bayesian analysis on mock signals from numerical simulations of a series of binary configurations with parameters similar to those found for GW150914. Overall, we find no evidence for a systematic bias relative to the statistical error of the original parameter recovery of GW150914 due to modeling approximations or modeling inaccuracies. However, parameter biases are found to occur for some configurations disfavored by the data of GW150914: for binaries inclined edge-on to the detector over a small range of choices of polarization angles, and also for eccentricities greater than ~0.05. For signals with higher signal-to-noise ratio than GW150914, or in other regions of the binary parameter space (lower masses, larger mass ratios, or higher spins), we expect that systematic errors in current waveform models may impact gravitational-wave measurements, making more accurate models desirable for future observations.
118 citations
Authors
Showing all 7857 results
Name | H-index | Papers | Citations |
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Pulickel M. Ajayan | 176 | 1223 | 136241 |
Suvadeep Bose | 154 | 960 | 129071 |
Subir Sarkar | 149 | 1542 | 144614 |
Sw. Banerjee | 146 | 1906 | 124364 |
Dipanwita Dutta | 143 | 1651 | 103866 |
Ajit Kumar Mohanty | 141 | 1124 | 93062 |
Tariq Aziz | 138 | 1646 | 96586 |
Andrew Mehta | 137 | 1444 | 101810 |
Suchandra Dutta | 134 | 1265 | 87709 |
Kajari Mazumdar | 134 | 1295 | 94253 |
Bobby Samir Acharya | 133 | 1121 | 100545 |
Gobinda Majumder | 133 | 1523 | 87732 |
Eric Conte | 132 | 1206 | 84593 |
Prashant Shukla | 131 | 1341 | 85287 |
Alessandro Montanari | 131 | 1387 | 93071 |