The<i>m</i>–<i>z</i>relation for Type Ia supernovae: safety in numbers or safely without worry?

Helbig, Phillip

doi:10.1093/mnras/stv1796

Cited by 6 publications

(3 citation statements)

References 17 publications

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“…In the past decade, various works have claimed that measuring a very small curvature today should not be considered as an argument in favor of cosmic inflation or its alternatives, as it could also be "natural" in a purely decelerating Friedmann-Lemaître universe [122][123][124]. In other words, there is no need for cosmological inflation to solve the flatness problem because there is no flatness problem at all.…”

Section: The Flatness Problemmentioning

confidence: 99%

Inflation after Planck: Judgment Day

Chowdhury,

Martin,

Ringeval

et al. 2019

Preprint

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Inflation is considered as the best theory of the early universe by a very large fraction of cosmologists. However, the validity of a scientific model is not decided by counting the number of its supporters and, therefore, this dominance cannot be taken as a proof of its correctness. Throughout its history, many criticisms have been put forward against inflation. The final publication of the Planck cosmic microwave background data represents a benchmark time to study their relevance and to decide whether inflation really deserves its supremacy. In this paper, we categorize the criticisms against inflation, go through all of them in the light of what is now observationally known about the early universe, and try to infer and assess the scientific status of inflation. Although we find that important questions still remain open, we conclude that the inflationary paradigm is not in trouble but, on the contrary, has rather been strengthened by the Planck data.

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Section: The Flatness Problemmentioning

confidence: 99%

Inflation after Planck: Judgment Day

Chowdhury,

Martin,

Ringeval

et al. 2019

Preprint

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“…Further, it has been shown [27] that for Ω Λ = 0 models, there exist non-flat FRW models for which Ω o ∼ 1 throughout the entire history of the universe, and that these really are not fine-tuned models. From an examination of the flatness problem quantitatively for all cosmological models it has been concluded [28] that the flatness problem does not exist, not only for the cosmological models corresponding to the currently popular values of λ and Ω o values but indeed for all FRW models with λ = 0.…”

Section: Flatness Problemmentioning

confidence: 99%

Horizon, homogeneity and flatness problems -- do their resolutions really depend upon inflation?

Singal¹

2016

Preprint

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We argue that the horizon problem arises in world models based on Robertson-Walker line element where homogeneity and isotropy (cosmological principle) is guaranteed at all epochs. All that happens is that in such a universe, light signals in a finite time might not be covering all available space. Also the flatness problem, as it is posed, is not even falsifiable. The usual argument offered in literature is that the present density of the universe is very close to the critical density value and that the universe must be flat since otherwise, in past at ∼ 10 −35 second (near the epoch of inflation), any departures of density from the critical density value will be extremely low (of the order ∼ 10 −53 ), requiring a sort of fine tuning. We show that even if the present value of the density parameter were very different, still at 10 −35 second it would differ from unity by the same fraction. Thus a use of fine tuning argument to promote k = 0 model amounts to a priori rejection of all models with k = 0. Without casting any whatsoever aspersions on the inflationary theories, we point out that one cannot use homogeneity and flatness in support of inflation.

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“…Hence, =0 are not necessarily 'Vacuum equations' in the sense of a completely empty Universe. On the other hand, attempts to use solutions of equation (1) with ≠0 in Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmology have led to many intractable problems such as the hypothetical non-baryonic dark matter [4], dark energy and the cosmological constant problem [5], the horizon problem [6] and the flatness problem [7] which show no signs of going away.…”

mentioning

confidence: 99%

Unified Theory Of Gravity and Electromagnetism : Classical and Quantum Aspects

Avik@¹

2021

Preprint

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A unified classical theory of gravity and electromagnetism with a torsion vector Г_i≠ 0, proposed by S N Bose in 1952, is introduced. In this theory, the torsion vector acts as a magnetic current and it is shown that (i) the electromagnetism is invariant under continuous Heaviside–Larmor transformations and (ii) the electric and magnetic charges are topologically quantised, satisfying the Dirac quantisation condition, without implying any Dirac string provided Г_iis curl-less.

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Them–zrelation for Type Ia supernovae: safety in numbers or safely without worry?

Cited by 6 publications

References 17 publications

Inflation after Planck: Judgment Day

Inflation after Planck: Judgment Day

Horizon, homogeneity and flatness problems -- do their resolutions really depend upon inflation?

Unified Theory Of Gravity and Electromagnetism : Classical and Quantum Aspects

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