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Title: Point splitting renormalization of Schwinger induced current in de Sitter spacetime

Abstract

The covariant and gauge invariant calculation of the current expectation value in the homogeneous electric field in 1+3 dimensional de Sitter spacetime is shown. The result accords with previous work obtained by using adiabatic subtraction scheme. We therefore conclude the counterintuitive behaviors of the current in the infrared (IR) regime such as IR hyperconductivity and negative current are not artifacts of the renormalization scheme, but are real IR effects of the spacetime.

Authors:
 [1];  [2];  [1];  [2];  [3]
  1. Research Center for the Early Universe (RESCEU), Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033 (Japan)
  2. (Japan)
  3. (Kavli IPMU),WPI, UTIAS, The University of Tokyo, Kashiwa, Chiba, 277-8583 (Japan)
Publication Date:
Sponsoring Org.:
SCOAP3, CERN, Geneva (Switzerland)
OSTI Identifier:
22572115
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2016; Journal Issue: 07; Other Information: PUBLISHER-ID: JCAP07(2016)012; OAI: oai:repo.scoap3.org:16337; cc-by Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSMOLOGICAL INFLATION; DE SITTER GROUP; DE SITTER SPACE; ELECTRIC FIELDS; EXPECTATION VALUE; FOUR-DIMENSIONAL CALCULATIONS; GAUGE INVARIANCE; INFLATIONARY UNIVERSE; INFRARED DIVERGENCES; MAGNETIC FIELDS; QUANTUM COSMOLOGY; RENORMALIZATION; SPACE-TIME

Citation Formats

Hayashinaka, Takahiro, Department of Physics, Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033, Yokoyama, Jun’ichi, Department of Physics, Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033, and Kavli Institute for the Physics and Mathematics of the Universe. Point splitting renormalization of Schwinger induced current in de Sitter spacetime. United States: N. p., 2016. Web. doi:10.1088/1475-7516/2016/07/012.
Hayashinaka, Takahiro, Department of Physics, Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033, Yokoyama, Jun’ichi, Department of Physics, Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033, & Kavli Institute for the Physics and Mathematics of the Universe. Point splitting renormalization of Schwinger induced current in de Sitter spacetime. United States. doi:10.1088/1475-7516/2016/07/012.
Hayashinaka, Takahiro, Department of Physics, Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033, Yokoyama, Jun’ichi, Department of Physics, Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033, and Kavli Institute for the Physics and Mathematics of the Universe. 2016. "Point splitting renormalization of Schwinger induced current in de Sitter spacetime". United States. doi:10.1088/1475-7516/2016/07/012.
@article{osti_22572115,
title = {Point splitting renormalization of Schwinger induced current in de Sitter spacetime},
author = {Hayashinaka, Takahiro and Department of Physics, Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033 and Yokoyama, Jun’ichi and Department of Physics, Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033 and Kavli Institute for the Physics and Mathematics of the Universe},
abstractNote = {The covariant and gauge invariant calculation of the current expectation value in the homogeneous electric field in 1+3 dimensional de Sitter spacetime is shown. The result accords with previous work obtained by using adiabatic subtraction scheme. We therefore conclude the counterintuitive behaviors of the current in the infrared (IR) regime such as IR hyperconductivity and negative current are not artifacts of the renormalization scheme, but are real IR effects of the spacetime.},
doi = {10.1088/1475-7516/2016/07/012},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 07,
volume = 2016,
place = {United States},
year = 2016,
month = 7
}
  • We explore Schwinger effect of spin 1/2 charged particles with static electric field in 1+3 dimensional de Sitter spacetime. We analytically calculate the vacuum expectation value of the spinor current which is induced by the produced particles in the electric field. The renormalization is performed with the adiabatic subtraction scheme. We find that the current becomes negative, namely it flows in the direction opposite to the electric field, if the electric field is weaker than a certain threshold value depending on the fermion mass, which is also known to happen in the case of scalar charged particles in 1+3 demore » Sitter spacetime. Contrary to the scalar case, however, the IR hyperconductivity is absent in the spinor case.« less
  • We derive the effective Lagrangian of a magnetic field in the context of amassless scalar QED coupled to gravity in de Sitter spacetime. It is found thatthe magnetic field is produced at the beginning of the inflation in a minimallycoupled scalar QED, and that the intensity /ital B/ is proportional to/ital eH//sup 2/ (/ital H/ is the Hubble constant). When/ital H/=10/sup 15/ GeV, /ital B//similar to/1.3/times/10/sup 47/ G.
  • We study the behavior of the vacuum expectation value of /vert bar//phi//vert bar//sup 2/ under an external magnetic field in de Sitter spacetime, where /phi/ is a charged scalar field. It is found that if a strong magnetic field is generated at early time in the inflationary Universe, the vacuum expectation value becomes negative and an instability of the vacuum arises. However, as time passes, this instability disappears and the vacuum becomes stable, except for massless and minimally coupled fields. Thus the magnetic field produced in the early Universe provides an important effect to the symmetry behavior of the inflationary-Universemore » model.« less
  • The breaking of global continuous symmetries in two-dimensional flat spacetime and in four-dimensional de Sitter spacetime is investigated. Infrared divergences require physically allowable quantum states in these spaces to break Lorentz or de Sitter invariance, resulting in two-point functions which are explicitly time dependent. Field expectation values which break the global symmetry must decay in time, but it is possible to have a state which exhibits broken symmetry for a finite time. It is also possible for field correlations and energy density produced by a broken-symmetry state to persist after the symmetry has been restored.
  • We consider Schwinger pair production in 1+1 dimensional de Sitter space, filled with a constant electric field E. This can be thought of as a model for describing false vacuum decay beyond the semiclassical approximation, where pairs of a quantum field φ of mass m and charge e play the role of vacuum bubbles. We find that the adiabatic ''in'' vacuum associated with the flat chart develops a space-like expectation value for the current J, which manifestly breaks the de Sitter invariance of the background fields. We derive a simple expression for J(E), showing that both ''upward'' and ''downward'' tunnelingmore » contribute to the build-up of the current. For heavy fields, with m{sup 2} >> eE,H{sup 2}, the current is exponentially suppressed, in agreement with the results of semiclassical instanton methods. Here, H is the inverse de Sitter radius. On the other hand, light fields with m || H lead to a phenomenon of infrared hyperconductivity, where a very small electric field mH∼« less