Zobrazeno 1 - 10
of 18
pro vyhledávání: '"Karthik Rajeev"'
Publikováno v:
Journal of High Energy Physics, Vol 2024, Iss 9, Pp 1-28 (2024)
Abstract We use the worldline formalism to derive Bern-Kosower type Master Formulae for the tree-level scattering of a charged particle and an arbitrary number of photons on impulsive PP-waves, where the coupling of the PP-wave to matter is treated f
Externí odkaz:
https://doaj.org/article/e4887c1c388d428cb4acb3a4ca7b9e99
Autor:
Karthik Rajeev
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 79, Iss 11, Pp 1-15 (2019)
Abstract We consider the backreaction of a quantum system q on an effectively classical degree of freedom C that is interacting with it. The backreaction equation based on the standard path integral formalism gives the so-called ‘in-out’ backreac
Externí odkaz:
https://doaj.org/article/c8ae49ade5884a6da22c60a79815ca64
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 78, Iss 10, Pp 1-12 (2018)
Abstract A spatially homogeneous, time-dependent, electric field can produce charged particle pairs from the vacuum. When the electric field is constant, the mean number of pairs which are produced depends on the electric field and the coupling const
Externí odkaz:
https://doaj.org/article/efa77892b9fb457da6f331b2f65700e1
Akademický článek
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Autor:
Karthik Rajeev
We consider a proposal to define the wave function of the Universe as a sum over spacetimes that eventually inflate. In the minisuperspace model, we explicitly show that a simple family of initial conditions, parametrized by a positive real number $a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::05d5520dbb32f9bd8071eb369a2ae872
http://arxiv.org/abs/2112.04522
http://arxiv.org/abs/2112.04522
Autor:
Karthik Rajeev
Publikováno v:
Physical Review
We demonstrate that the positive frequency modes for a complex scalar field in a constant electric field (Schwinger modes), in three different gauges, can be represented as exact Lorentzian worldline path integral amplitudes. Although the mathematica
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ac88a37deedd8533f4edf54decb0e4b2
https://doi.org/10.1103/physrevd.104.105014
https://doi.org/10.1103/physrevd.104.105014
Publikováno v:
Physical Review D. 103
Bouncing models are alternatives to inflationary cosmology that replace the initial Big-Bang singularity by a `bouncing' phase. A deeper understanding of the initial conditions of the universe, in these scenarios, requires knowledge of quantum aspect
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::73630b311b66c0cbfd49019dba0bc7d4
https://doi.org/10.1103/physrevd.103.106008
https://doi.org/10.1103/physrevd.103.106008
Autor:
Karthik Rajeev
Publikováno v:
European Physical Journal
European Physical Journal C: Particles and Fields, Vol 79, Iss 11, Pp 1-15 (2019)
European Physical Journal C: Particles and Fields, Vol 79, Iss 11, Pp 1-15 (2019)
We consider the backreaction of a quantum system $q$ on an effectively classical degree of freedom $C$ that is interacting with it. The backreaction equation based on the standard path integral formalism gives the so-called `in-out' backreaction equa
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ee9e72902b96e5d0e593d43dee7de9e3
http://arxiv.org/abs/2001.02543
http://arxiv.org/abs/2001.02543
Autor:
Karthik Rajeev, Thanu Padmanabhan
In flat spacetime, two inequivalent vacuum states which arise rather naturally are the Rindler vacuum (R) and the Minkowski vacuum (M). We disuss several aspects of the Rindler vacuum, concentrating on the propagator and Schwinger (heat) kernel defin
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8fa20ebd7c703de305f97ca4f0d9d037
http://arxiv.org/abs/1906.09278
http://arxiv.org/abs/1906.09278
We discuss several aspects of particle production in: (a) time dependent electric field and (b) expanding Friedmann background. In the first part of the paper, we provide an algebraic mapping between the differential equations describing these two ph
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b26ec71e5be1951704c1d6fd9b3ca4e7
http://arxiv.org/abs/1904.03207
http://arxiv.org/abs/1904.03207