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Title: Cosmological constant problem and renormalized vacuum energy density in curved background

Abstract

The current vacuum energy density observed as dark energy ρ{sub dark}≅ 2.5×10{sup −47} GeV{sup 4} is unacceptably small compared with any other scales. Therefore, we encounter serious fine-tuning problem and theoretical difficulty to derive the dark energy. However, the theoretically attractive scenario has been proposed and discussed in literature: in terms of the renormalization-group (RG) running of the cosmological constant, the vacuum energy density can be expressed as ρ{sub vacuum}≅ m {sup 2} H {sup 2} where m is the mass of the scalar field and rather dynamical in curved spacetime. However, there has been no rigorous proof to derive this expression and there are some criticisms about the physical interpretation of the RG running cosmological constant. In the present paper, we revisit the RG running effects of the cosmological constant and investigate the renormalized vacuum energy density in curved spacetime. We demonstrate that the vacuum energy density described by ρ{sub vacuum}≅ m {sup 2} H {sup 2} appears as quantum effects of the curved background rather than the running effects of cosmological constant. Comparing to cosmological observational data, we obtain an upper bound on the mass of the scalar fields to be smaller than the Planck mass, m ∼<more » M {sub Pl}.« less

Authors:
 [1];  [2]
  1. Theory Center, IPNS, KEK, Tsukuba 305-0801, Ibaraki (Japan)
  2. The Graduate University of Advanced Studies (Sokendai), Tsukuba 305-0801, Ibaraki (Japan)
Publication Date:
OSTI Identifier:
22676182
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 06; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; COSMOLOGICAL CONSTANT; ENERGY DENSITY; GEV RANGE; MASS; NONLUMINOUS MATTER; RENORMALIZATION; SCALAR FIELDS; SPACE-TIME

Citation Formats

Kohri, Kazunori, and Matsui, Hiroki, E-mail: kohri@post.kek.jp, E-mail: matshiro@post.kek.jp. Cosmological constant problem and renormalized vacuum energy density in curved background. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/06/006.
Kohri, Kazunori, & Matsui, Hiroki, E-mail: kohri@post.kek.jp, E-mail: matshiro@post.kek.jp. Cosmological constant problem and renormalized vacuum energy density in curved background. United States. doi:10.1088/1475-7516/2017/06/006.
Kohri, Kazunori, and Matsui, Hiroki, E-mail: kohri@post.kek.jp, E-mail: matshiro@post.kek.jp. Thu . "Cosmological constant problem and renormalized vacuum energy density in curved background". United States. doi:10.1088/1475-7516/2017/06/006.
@article{osti_22676182,
title = {Cosmological constant problem and renormalized vacuum energy density in curved background},
author = {Kohri, Kazunori and Matsui, Hiroki, E-mail: kohri@post.kek.jp, E-mail: matshiro@post.kek.jp},
abstractNote = {The current vacuum energy density observed as dark energy ρ{sub dark}≅ 2.5×10{sup −47} GeV{sup 4} is unacceptably small compared with any other scales. Therefore, we encounter serious fine-tuning problem and theoretical difficulty to derive the dark energy. However, the theoretically attractive scenario has been proposed and discussed in literature: in terms of the renormalization-group (RG) running of the cosmological constant, the vacuum energy density can be expressed as ρ{sub vacuum}≅ m {sup 2} H {sup 2} where m is the mass of the scalar field and rather dynamical in curved spacetime. However, there has been no rigorous proof to derive this expression and there are some criticisms about the physical interpretation of the RG running cosmological constant. In the present paper, we revisit the RG running effects of the cosmological constant and investigate the renormalized vacuum energy density in curved spacetime. We demonstrate that the vacuum energy density described by ρ{sub vacuum}≅ m {sup 2} H {sup 2} appears as quantum effects of the curved background rather than the running effects of cosmological constant. Comparing to cosmological observational data, we obtain an upper bound on the mass of the scalar fields to be smaller than the Planck mass, m ∼< M {sub Pl}.},
doi = {10.1088/1475-7516/2017/06/006},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 06,
volume = 2017,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2017},
month = {Thu Jun 01 00:00:00 EDT 2017}
}
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  • Increasing improvements in the independent determinations of the Hubble constant and the age of the universe now seem to indicate that we need a small nonvanishing cosmological constant to make the two independent observations consistent with each other. The cosmological constant can be physically interpreted as due to the vacuum energy of quantized fields. To make the cosmological observations consistent with each other we would need a vacuum energy density {rho}{sub {ital v}}{similar_to}(10{sup {minus}3} eV){sup 4} today (in the cosmological units {h_bar}={ital c}={ital k}=1). It is argued in this paper that such a vacuum energy density is natural in themore » context of phase transitions linked to massive neutrinos. In fact, the neutrino masses required to provide the right vacuum energy scale to remove the age versus Hubble constant discrepancy are consistent with those required to solve the solar neutrino problem by the MSW mechanism. {copyright} 1995 The American Physical Society.« less
  • The phenomenon of emergent physics in condensed-matter many-body systems has become the paradigm of modern physics, and can probably also be applied to high-energy physics and cosmology. This encouraging fact comes from the universal properties of the ground state (the analog of the quantum vacuum) in fermionic many-body systems, described in terms of the momentum-space topology. In one of the two generic universality classes of fermionic quantum vacua the gauge fields, chiral fermions, Lorentz invariance, gravity, relativistic spin, and other features of the Standard Model gradually emerge at low energy. The condensed-matter experience provides us with some criteria for selectingmore » the proper theories in particle physics and gravity, and even suggests specific solutions to different fundamental problems. In particular, it provides us with a plausible mechanism for the solution of the cosmological constant problem, which I will discuss in some detail.« less