Strong limits on the possible decay of the vacuum energy into CDM or CMB photons

Opher, R.; Pelinson, Ana

doi:10.1590/s0103-97332005000700052

Cited by 13 publications

(16 citation statements)

References 8 publications

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“…In particular when CMB photon number is not conserved, β can be constrained by the distance duality relation violation (Avgoustidis et al 2012, and references therein) or by combining the CMB and galaxy distribution (as in, e.g., Opher & Pelinson 2005). These indirect measurements yield β = 0.010 ± 0.020 and β ≤ 0.0034, consistent with our analysis.…”

Section: Discussionsupporting

confidence: 87%

Measurement of theT_CMBevolution from the Sunyaev-Zel’dovich effect

Hurier¹,

Aghanim²,

Douspis³

et al. 2014

A&A

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In the standard hot cosmological model, the black-body temperature of the cosmic microwave background (CMB), T CMB , increases linearly with redshift. Across the line of sight CMB photons interact with the hot (∼10 7−8 K ) and diffuse gas of electrons from galaxy clusters. This interaction leads to the well-known thermal Sunyaev-Zel'dovich effect (tSZ), which produces a distortion of the black-body emission law, depending on T CMB . Using tSZ data from the Planck satellite, it is possible to constrain T CMB below z = 1. Focusing on the redshift dependance of T CMB , we obtain T CMB (z) = (2.726 ± 0.001) × (1 + z) 1−β K with β = 0.009 ± 0.017, which improves on previous constraints. Combined with measurements of molecular species absorptions, we derive β = 0.006 ± 0.013. These constraints are consistent with the standard (i.e. adiabatic, β = 0) Big-Bang model.

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Section: Discussionsupporting

confidence: 87%

Measurement of theT_CMBevolution from the Sunyaev-Zel’dovich effect

Hurier¹,

Aghanim²,

Douspis³

et al. 2014

A&A

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“…But from BBN to the present, the degree of the deviation is almost negligible ( ∆η η ≤ 10 −5 ) [27,28]. The impact of dark energy on η is mainly due to the possibility that dark energy could decay into CMB, but the decay rate of dark energy must be sufficiently small to be in accordance with observations [29][30][31][32][33]. Considering low-amplitude and large-scale fluctuations, the evolution of η may change with the region of the universe [34].…”

Section: Introductionmentioning

confidence: 90%

Constraints on running vacuum models with the baryon-to-photon ratio

Yu,

Yang,

2021

Preprint

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We study the influence of running vacuum on the baryon-to-photon ratio in running vacuum models (RVMs). When there exists non-minimal coupling between photons and other matter in the expanding universe, the energy-momentum tensor of photons is no longer conserved, but the energy of photons could remain conserved. We discuss the conditions for the energy conservation of photons in RVMs. The photon number density and baryon number density, from the epoch of photon decoupling to the present day, are obtained in the context of RVMs by assuming that photons and baryons can be coupled to running vacuum, respectively. Both cases cause the baryon-to-photon ratio to no longer be a constant. However the evolution of the baryon-to-photon ratio is strictly constrained by observations. It is found that if the dynamic term of running vacuum is indeed coupled to photons or baryons, the coefficient of the dynamic term must be extremely small, which is unnatural. Therefore, our study basically rules out the possibility that running vacuum is coupled to photons or baryons in RVMs.

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“…Some researchers believe that it may flow into other matter fields, such as dark matter or dark energy, so as to ensure the total energy conservation of the universe. The current research on photons coupling to dark matter or dark energy [61,62,63,64,65,66,67,68,69] has seldom paid attention to the issue of the total energy of the universe. Next, we focus on the coupling between photons and other matter fields.…”

Section: Energy Conservation In Cosmologymentioning

confidence: 99%

On the correspondence between energy conservation and energy-momentum tensor conservation in cosmology

Yu,

Gu,

Luo

et al. 2021

Preprint

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The correspondence between the thermodynamic energy equation satisfied by a closed co-moving volume and the conservation equation satisfied by the energy-momentum tensor of the matter inside the co-moving volume is extended to a more general system with an arbitrary cosmological horizon and a heat source. The energy of the system consisting of a cosmological horizon and its internal matter could be conserved by defining a surface energy on the horizons. Therefore, energy conservation and energymomentum tensor conservation can always be consistent for such a system. On the other hand, from the perspective of classical thermodynamics, one can define an effective pressure at the cosmological horizon to guarantee that the thermodynamic energy equation inside the horizon is consistent with the energymomentum tensor conservation equation of the matter inside the horizon. These systems can satisfy the generalized second law of thermodynamics under appropriate conditions. The definitions of the surface energy and the effective pressure are extended to the gravity theory with non-minimal coupling between geometry and matter, in which geometry could be regarded as a heat source.

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Strong limits on the possible decay of the vacuum energy into CDM or CMB photons

Cited by 13 publications

References 8 publications

Measurement of theT_CMBevolution from the Sunyaev-Zel’dovich effect

Measurement of theT_CMBevolution from the Sunyaev-Zel’dovich effect

Constraints on running vacuum models with the baryon-to-photon ratio

On the correspondence between energy conservation and energy-momentum tensor conservation in cosmology

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Strong limits on the possible decay of the vacuum energy into CDM or CMB photons

Cited by 13 publications

References 8 publications

Measurement of theTCMBevolution from the Sunyaev-Zel’dovich effect

Measurement of theTCMBevolution from the Sunyaev-Zel’dovich effect

Constraints on running vacuum models with the baryon-to-photon ratio

On the correspondence between energy conservation and energy-momentum tensor conservation in cosmology

Contact Info

Product

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Measurement of theT_CMBevolution from the Sunyaev-Zel’dovich effect

Measurement of theT_CMBevolution from the Sunyaev-Zel’dovich effect