Browsing Das, Saurya by Title

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  • Adiabatic quantum computation and Deutsch's algorithm 
    Das, Saurya; Kobes, Randy; Kunstatter, Gabor (American Physical SocietyUniversity of WinnipegWinnipeg Institute for Theoretical Physicshttps://doi.org/10.1103/PhysRevA.65.062310, 2002)
    We show that by a suitable choice of a time-dependent Hamiltonian, Deutsch’s algorithm can be implemented by an adiabatic quantum computer. We extend our analysis to the Deutsch-Jozsa problem and estimate the required ...
  • Aspects of Planckian scattering beyond the eikonal 
    Das, Saurya; Majumdar, Parthasarathi (Indian Academy of SciencesInstitute of Mathematical Sciences (India)https://www.ias.ac.in/article/fulltext/pram/051/03-04/0413-0419, 1998)
    We discuss an approach to compute two-particle scattering amplitudes for spinless light particles colliding at Planckian centre-of-mass energies, with increasing momentum transfer away from the eikonal limit. The leading ...
  • Black hole emission rates and the AdS/CFT correspondence 
    Das, Saurya; Dasgupta, Arundhati (SISSAPennsylvania State UniversityInstitute of Mathematical Sciences (India), 1999)
    We study the emission rates of scalar, spinor and vector particles from a 5 dimensional black hole for arbitrary partial waves. The solution is lifted to 6 dimensions, and the near horizon BTZ S3 geometry of the black ...
  • Black hole thermodynamics: entropy, information and beyond 
    Das, Saurya (Arts and ScienceDepartment of PhysicsUniversity of Lethbridgehttps://www.ias.ac.in/article/fulltext/pram/063/04/0797-0815, 2015-12-16)
    We review some recent advances in black hole thermodynamics, including statistical mechanical origins of black hole entropy and its leading order corrections, from the viewpoints of various quantum gravity theories. We ...
  • Can MOND type hypotheses be tested in a free fall laboratory environment? 
    Das, Saurya; Patitsas, Steve (Arts and ScienceDepartment of Physics and AstronomyUniversity of Lethbridgehttps://doi.org/10.1103/PhysRevD.87.107101, 2015-12-15)
    The extremely small accelerations of objects required for the the onset of modified Newtonian dynamics, or MOND, makes testing the hypothesis in conventional terrestrial laboratories virtually impossible. This is due to ...
  • Charged black holes in generalized dilaton-axion gravity 
    Sur, Sourav; Das, Saurya; SenGupta, Soumitra (Arts and ScienceDepartment of PhysicsInstitute of PhysicsUniversity of LethbridgeIndian Association for the Cultivation of Science, 2015-12-16)
    We study generic Einstein-Maxwell-Kalb-Ramond-dilaton actions, and derive conditions under which they give rise to static, spherically symmetric black hole solutions. We obtain new asymptotically flat and non-flat black ...
  • Conserved quantities in Kerr-anti-de Sitter spacetimes in various dimensions 
    Das, Saurya; Mann, Robert B. (SISSAPennsylvania State UniversityUniversity of Waterloohttp://iopscience.iop.org/1126-6708/2000/08/033, 2000)
    We compute the conserved charges for Kerr anti-de Sitter spacetimes in various dimensions using the conformal and the counterterm prescriptions. We show that the conserved charge corresponding to the global timelike ...
  • Cosmic coincidence or graviton mass? 
    Das, Saurya (Arts and ScienceDepartment of Physics and AstronomyUniversity of Lethbridgehttps://doi.org/10.1142/S0218271814420176, 2015-12-23)
    Using the quantum corrected Friedmann equation, obtained from the quantum Raychudhuri equation, and assuming a small mass of the graviton (but consistent with observations and theory), we propose a resolution of the ...
  • Cosmological constant, brane tension and large hierarchy in a generalized Randall-Sundrum braneworld scenario 
    Das, Saurya; Maity, Debaprasad; SenGupta, Soumitra (Arts and ScienceDepartment of PhysicsUniversity of LethbridgeThe Institute of Mathematical Sciences (India)Indian Association for the Cultivation of Science, 2015-12-22)
    We consider a generalized Randall Sundrum (RS) brane world scenario with a cosmological constant induced on the visible brane. We show that for < 0, resolution of the hierarchy problem requires an upper bound on the ...
  • Cosmology from quantum potential 
    Ali, Ahmed Farag; Das, Saurya (Arts and ScienceDepartment of Physics and AstronomyBenha UniversityUniversity of Lethbridge, 2016-01-20)
    It was shown recently that replacing classical geodesics with quantal (Bohmian) trajectories gives rise to a quantum corrected Raychaudhuri equation (QRE). Here we derive the second order Friedmann equations from the ...
  • Das and Vagenas reply 
    Das, Saurya; Vagenas, Elias C. (Arts and ScienceDepartment of PhysicsUniversity of LethbridgeAcademy of Athenshttps://doi.org/10.1103/PhysRevLett.104.119002, 2015-12-15)
    A reply to the Comment by M. M. Ettefaghi and S. M. Fazeli
  • Discreteness of space from GUP II: relativistic wave equations 
    Das, Saurya; Vagenas, Elias C.; Ali, Ahmed Farag (Arts and ScienceDepartment of PhysicsUniversity of LethbridgeAcademy of Athens, 2015-12-22)
    Various theories of Quantum Gravity predict modifications of the Heisenberg Uncertainty Prin- ciple near the Planck scale to a so-called Generalized Uncertainty Principle (GUP). In some recent papers, we showed that the ...
  • Discreteness of space from GUP in a weak gravitational field 
    Deb, Soumen; Das, Saurya; Vagenas, Elias C. (ElsevierArts and ScienceDepartment of Physics & AstronomyUniversity of LethbridgeKuwait University, 2016)
    Quantum gravity effects modify the Heisenberg's uncertainty principle to a generalized uncertainty principle (GUP). Earlier work showed that the GUP-induced corrections to the Schrödinger equation, when applied to a ...
  • Discreteness of space from the generalized uncertainty principle 
    Ali, Ahmed Farag; Das, Saurya; Vagenas, Elias C. (Arts and ScienceDepartment of PhysicsUniversity of LethbridgeAcademy of Athens, 2015-12-15)
    Various approaches to Quantum Gravity (such as String Theory and Doubly Special Relativity), as well as black hole physics predict a minimum measurable length, or a maximum observable momentum, and related modifications ...
  • Effect of the generalized uncertainty principle on post-inflation preheating 
    Chemissany, Wissam; Das, Saurya; Ali, Ahmed Farag; Vagenas, Elias C. (Arts and ScienceDepartment of Physics and AstronomyKatholieke Universiteit LeuvenUniversity of LethbridgeAcademy of Athenshttps://doi.org/10.1088/1475-7516/2011/12/017, 2016-01-19)
    We examine effects of the Generalized Uncertainty Principle, predicted by various theories of quantum gravity to replace the Heisenberg’s uncertainty principle near the Planck scale, on post inflation preheating in ...
  • Eikonal particle scattering and dilaton gravity 
    Das, Saurya; Majumdar, Parthasarathi (American Physical SocietyInstitute of Mathematical Sciences (India)https://doi.org/10.1103/PhysRevD.55.2090, 1997)
    Approximating light charged pointlike particles in terms of ~nonextremal! dilatonic black holes is shown to lead to certain pathologies in Planckian scattering in the eikonal approximation, which are traced to the presence ...
  • Electromagnetic and gravitational scattering at Planckian energies 
    Das, Saurya; Majumdar, Parthasarathi (American Physical SocietyInstitute of Mathematical SciencesInternational Centre for Theoretical Physicshttps://doi.org/10.1103/PhysRevD.51.5664, 1995)
    The scattering of pointlike particles at a very large center-of-mass energies and fixed low momentum transfers, occurring due to both their electromagnetic and gravitational interactions, is reexamined in the particular ...
  • Electromagnetic charge-monopole versus gravitational scattering at Planckian energies 
    Das, Saurya; Majumdar, Parthasarathi (American Physical SocietyInstitute of Mathematical Scienceshttps://doi.org/10.1103/PhysRevLett.72.2524, 1994)
    The amplitude for the scattering of a point magnetic monopole and a point charge, at center-of- mass energies much larger than the masses of the particles, and in the limit of low momentum transfer, is shown to be ...
  • Entanglement as a source of black hole entropy 
    Das, Saurya; Shankaranarayanan, S. (Arts and ScienceDepartment of PhysicsUniversity of LethbridgeMax-Planck-Institut für Gravitationphysikhttps://doi.org/10.1088/1742-6596/68/1/012015, 2015-12-16)
    We review aspects of black hole thermodynamics, and show how entanglement of a quantum field between the inside and outside of a horizon can account for the areaproportionality of black hole entropy, provided the field ...
  • Entanglement entropy in all dimensions 
    Braunstein, Samuel L.; Das, Saurya; Shankaranarayanan, S. (Arts and ScienceDepartment of PhysicsUniversity of YorkUniversity of LethbridgeIndian Institute of Science Education and Research, 2015-12-15)
    It has long been conjectured that the entropy of quantum fields across boundaries scales as the boundary area. This conjecture has not been easy to test in spacetime dimensions greater than four because of divergences ...