Vacuum energy in cosmic dynamics

Blome, Hans Joachim; Priester, Wolfgang

doi:10.1007/bf00650158

Cited by 23 publications

(17 citation statements)

References 12 publications

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“…However, observations of the unexpected SNe Ia dimming motivated large-scale systematic searches for SNe Ia and resulted in a rapid extension of supernovae compilations (Sullivan et al 2011;Suzuki et al 2012;Campbell et al 2013;Betoule et al 2014;Jones et al 2018;Scolnic et al 2018). This surprising phenomenon was explained by an accelerating expansion of the Universe, and consequently a concept of the cosmological constant (Einstein 1917;Blome & Priester 1985;Carroll et al 1992) was revived and reintroduced as dark energy into the cosmological models (Weinberg 1989;Riess 2000;Sahni & Starobinsky 2000;Peebles & Ratra 2003).…”

Section: Introductionmentioning

confidence: 99%

Universe opacity and Type Ia supernova dimming

Vavryčuk

2019

Monthly Notices of the Royal Astronomical Society: Letters

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In this paper, I revoke a debate about an origin of Type Ia supernova (SN Ia) dimming. I argue that except for a commonly accepted accelerating expansion of the Universe, a conceivable alternative for explaining this observation is universe opacity caused by light extinction by intergalactic dust, even though it is commonly assumed that this effect is negligible. Using data of the Union2.1 SN Ia compilation, I find that the standard ΛCDM model and the opaque universe model fit the SN Ia measurements at redshifts z < 1.4 comparably well. The optimum solution for the opaque universe model is characterized by the B-band intergalactic opacity λ B = 0.10 ± 0.03 Gpc −1 and the Hubble constant H 0 = 68.0 ± 2.5 km s −1 Mpc −1 . The intergalactic opacity is higher than that obtained from independent observations but still within acceptable limits. This result emphasizes that the issue of the accelerating expansion of the Universe as the origin of the SN Ia dimming is not yet definitely resolved. Obviously, the opaque universe model as an alternative to the ΛCDM model is attractive, because it avoids puzzles and controversies associated with dark energy and the accelerating expansion.

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Section: Introductionmentioning

confidence: 99%

Universe opacity and Type Ia supernova dimming

Vavryčuk

2019

Monthly Notices of the Royal Astronomical Society: Letters

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“…A "big-bounce" model with a non-vanishing cosmological constant was considered by Blome and Priester [11] and compared with the model proposed in [9]. Later a "soft bang" model of an inflationary universe without the initial singularity was proposed by Rebhan [12].…”

Section: Introductionmentioning

confidence: 99%

A Weyl-Dirac cosmological model with DM and DE

Israelit

2010

Gen Relativ Gravit

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In the Weyl-Dirac (W-D) framework a spatially closed cosmological model is considered. It is assumed that the space-time of the universe has a chaotic Weylian microstructure but is described on a large scale by Riemannian geometry. Locally fields of the Weyl connection vector act as creators of massive bosons having spin 1. It is suggested that these bosons, called weylons, provide most of the dark matter in the universe. At the beginning the universe is a spherically symmetric geometric entity without matter. Primary matter is created by Dirac's gauge function very close to the beginning. In the early epoch, when the temperature of the universe achieves its maximum, chaotically oriented Weyl vector fields being localized in micro-cells create weylons. In the dust dominated period Dirac's gauge function is giving rise to dark energy, the latter causing the cosmic acceleration at present. This oscillatory universe has an initial radius identical to the Plank length = 1.616 exp (-33) cm, at present the cosmic scale factor is 3.21 exp (28) cm, while its maximum value is 8.54 exp (28) cm. All forms of matter are created by geometrically based functions of the W-D theory.

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“…For the range of 45-100 km s −1 Mpc −1 of today's Hubble constant H 0 , the critical density is estimated as ρ c = 0.5 − 2 × 10 −29 g/cm 3 . From local as well as large scale astronomical measurements, respectively, the macroscopically observed cosmological constant Λ is estimated [8] to be less than 4 × 10 −56 cm −2 . Since the vacuum energy may also be time-dependent at the early stages of the universe, the exact fine-tuning of the various vacuum contributions to a very small Λ in the low temperature regime of today appears to be one of the great mysteries about unification.…”

Section: Introduction: Einstein's Biggest Blundermentioning

confidence: 99%

Method of generating exact inflationary solutions

Schunck

Mielke

1994

Phys. Rev. D

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The mechanism of the initial inflation of the universe is based on gravitationally coupled scalar fields φ. Various scenarios are distinguished by the choice of an effective self-interaction potential U (φ) which simulates a temporarily non-vanishing cosmological term. Using the Hubble expansion parameter H as a new "time" coordinate, we can formally derive the general RobertsonWalker metric for a spatially flat cosmos. Our new method provides a classification of allowed inflationary potentials and is broad enough to embody all known exact solutions involving one scalar field as special cases. Moreover, we present new inflationary and deflationary exact solutions and can easily predict the influence of the form of U (φ) on density perturbations.

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Vacuum energy in cosmic dynamics

Cited by 23 publications

References 12 publications

Universe opacity and Type Ia supernova dimming

Universe opacity and Type Ia supernova dimming

A Weyl-Dirac cosmological model with DM and DE

Method of generating exact inflationary solutions

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