scholarly journals Resolving Hubble tension with the Milne model

2020 ◽  
Vol 29 (14) ◽  
pp. 2043025
Author(s):  
Ram Gopal Vishwakarma
Keyword(s):  
Hubble Constant ◽  
Big Bang ◽  
New Physics ◽  
Late Time ◽  
Standard Cosmology ◽  
Evolution Dynamics ◽  
Age Of The Universe ◽  
The Big Bang ◽  
The Universe ◽  
Big Bang Singularity

The recent measurements of the Hubble constant based on the standard [Formula: see text]CDM cosmology reveal an underlying disagreement between the early-Universe estimates and the late-time measurements. Moreover, as these measurements improve, the discrepancy not only persists but becomes even more significant and harder to ignore. The present situation places the standard cosmology in jeopardy and provides a tantalizing hint that the problem results from some new physics beyond the [Formula: see text]CDM model. It is shown that a nonconventional theory — the Milne model — which introduces a different evolution dynamics for the Universe, alleviates the Hubble tension significantly. Moreover, the model also averts some long-standing problems of the standard cosmology, for instance, the problems related with the cosmological constant, the horizon, the flatness, the Big Bang singularity, the age of the Universe and the nonconservation of energy.

scholarly journals COSMOLOGICAL CONSTRAINTS FOR THE COSMIC DEFECT THEORY

2011 ◽  
Vol 20 (06) ◽  
pp. 1039-1051 ◽  
Author(s):  
NINFA RADICELLA ◽  
MAURO SERENO ◽  
ANGELO TARTAGLIA
Keyword(s):  
Large Scale ◽  
Hubble Constant ◽  
Big Bang ◽  
Nuclear Species ◽  
Type Ia ◽  
Species Abundances ◽  
Age Of The Universe ◽  
Ia Supernovae ◽  
The Big Bang ◽  
The Universe

The cosmic defect theory has been confronted with four observational constraints: primordial nuclear species abundances emerging from the big bang nucleosynthesis; large scale structure formation in the Universe; cosmic microwave background acoustic scale; luminosity distances of type Ia supernovae. The test has been based on a statistical analysis of the a posteriori probabilities for three parameters of the theory. The result has been quite satisfactory and such that the performance of the theory is not distinguishable from that of the ΛCDM theory. The use of the optimal values of the parameters for the calculation of the Hubble constant and the age of the Universe confirms the compatibility of the cosmic defect approach with observations.

scholarly journals Tempeature Redshift of Photons

2020 ◽  
Author(s):  
Xiaoping Hu
Keyword(s):  
Dark Matter ◽  
Hubble Constant ◽  
Big Bang ◽  
New Physics ◽  
Current Theory ◽  
Big Bang Theory ◽  
Celestial Bodies ◽  
Expansion Force ◽  
The Big Bang ◽  
The Universe

This article presents a new theory on redshift of light from celestial bodies. Lately it has been found that the Hubble constant calculated from different methods discord so much that calls arise for new physics to explain. Also, in addition to many unsolved puzzles like dark matter and source of expansion force, we shall show in this article that the current theory of redshift implies a few hidden, unreasonale assumptions. By assuming photon has temperature and its thermal energy is fully converted to wave energy, this article shows that photon can have a new redshift called Temperature Redshift, which not only is more significant for remote stars or galaxies, but also better fits the observational data, including those used in Hubble constant calculation. As such, if true, this new theory not only adds to our new understanding of photons, but may totally change our current understanding of the Universe, i.e., the Big Bang theory.

scholarly journals The Hubble Constant

2000 ◽  
Vol 17 (1) ◽  
pp. 45-47 ◽  
Author(s):  
Jeremy Mould
Keyword(s):  
Globular Clusters ◽  
Hubble Space Telescope ◽  
Hubble Constant ◽  
Big Bang ◽  
Accelerating Universe ◽  
De Sitter ◽  
Age Of The Universe ◽  
Extragalactic Distance Scale ◽  
The Big Bang ◽  
The Universe

AbstractWith the completion of the Hubble Space Telescope (HST) Key Project on the Extragalactic Distance Scale, it is interesting to form the dimensionless quantity H0t0 by multiplying the Hubble Constant by the age of the Universe. In a matter dominated decelerating Universe with a density exceeding 0·26 of the critical value, H0t0 < 1; in an accelerating Universe with the same Ωm = 0·26, but dominated by vacuum energy with ΩV ≥ 1 – Ωm, H0t0 ≥ 1. If the first globular clusters formed 109 years after the Big Bang, then with 95% confidence H0t0 =1·0 ± 0·3. The classical Einstein–de Sitter cosmological model has H0t0 = ⅔.

The Alabama Insert

Think ◽  
2002 ◽  
Vol 1 (1) ◽  
pp. 7-20
Author(s):  
Richard Dawkins
Keyword(s):  
Public Schools ◽  
Life Forms ◽  
Big Bang ◽  
Human Beings ◽  
Text Book ◽  
Gallup Poll ◽  
The Bible ◽  
Age Of The Universe ◽  
The Big Bang ◽  
The Universe

Creationists believe that the Biblical account of the creation of the universe is literally true. God brought into existence the Earth and all its life forms in just six days. According to creationists, this event took place less than ten thousand years ago (they base their calculation of the age of the universe on the number of generations listed in the Bible).Creationists have succeeded in persuading large swathes of the general public that their theory is at least as scientifically respectable as the Big Bang/evolution alternative. A recent Gallup poll indicated that about 45% of US citizens currently believe that God created human beings ‘pretty much in [their] present form at one time or another within the last 10,000 years’.Two states, Arkansas and Louisiana, have even passed ‘balanced treatment’ laws requiring that creationism be taught alongside evolution in all state public schools. It was in Auburn, Alabama, shortly after that state required that a piece of paper be pasted into every biology school text book explaining why evolution is merely a ‘theory’ — and a highly questionable theory at that — that Richard Dawkins delivered the impromptu speech which forms the basis of the following.

scholarly journals Cosmology from quantum potential in a system of oscillating branes

2016 ◽  
Vol 31 (01) ◽  
pp. 1650004 ◽  
Author(s):  
Alireza Sepehri
Keyword(s):  
Generalized Uncertainty Principle ◽  
Scalar Fields ◽  
Big Bang ◽  
Fundamental String ◽  
Extra Energy ◽  
Age Of The Universe ◽  
The Big Bang ◽  
M Theory ◽  
Derivatives Of ◽  
The Universe

Recently, some authors proposed a new mechanism which gets rid of the Big Bang singularity and shows that the age of the universe is infinite. In this paper, we will confirm their results and predict that the universe may expand and contract many N fundamental strings decay to N M0–anti-M0-branes. Then, M0-branes join each other and build a M8-anti-M8 system. This system is unstable, broken and two anti-M4-branes, a compactified M4-brane, a M3-brane in addition to one M0-brane are produced. The M3-brane wraps around the compactified M4-brane and both of them oscillate between two anti-M4-branes. Our universe is located on the M3-brane and interacts with other branes by exchanging the M0-brane and some scalars in transverse directions. By wrapping of M3-brane, the contraction epoch of universe starts and some higher order of derivatives of scalar fields in the relevant action of branes are produced which are responsible for generating the generalized uncertainty principle (GUP). By oscillating the compactified M4-M3-brane and approaching one of anti-M4-branes, one end of M3-brane glues to the anti-M4-brane and other end remains sticking and wrapping around M4-brane. Then, by getting away of the M4-M3 system, M4 rolls, wrapped M3 opens and expansion epoch of universe begins. By closing the M4 to anti-M4, the mass of some scalars become negative and they make a transition to tachyonic phase. To remove these states, M4 rebounds, rolls and M3 wraps around it again. At this stage, expansion branch ends and universe enters a contraction epoch again. This process is repeated many times and universe expands and contracts due to oscillation of branes. We obtain the scale factor of universe in this system and find that its values only at t [Formula: see text] shrinks to zero. Thus, in our method, the Big Bang is replaced by the fundamental string and the age of universe is predicted to be infinite. Also, when tachyonic states disappear at the beginning of expansion branch, some extra energy is produced and leads to an increase in the velocity of opening of M3. In these conditions, our universe, which is located on this brane, expands very fast and experiences an inflation epoch. Finally, by reducing the fields in 11-dimensional M-theory to the fields in four-dimensional universe, we show that our theory matches with quantum field theory prescriptions.

scholarly journals Concordance cosmology?

2020 ◽  
Vol 499 (4) ◽  
pp. 4638-4645
Author(s):  
Youngsoo Park ◽  
Eduardo Rozo
Keyword(s):  
Cold Dark Matter ◽  
Hubble Constant ◽  
Big Bang ◽  
New Physics ◽  
Current Data ◽  
Data Sets ◽  
Late Time ◽  
Acoustic Oscillations ◽  
Dark Energy Survey ◽  
The Difference

ABSTRACT We propose a new intuitive metric for evaluating the tension between two experiments, and apply it to several data sets. While our metric is non-optimal, if evidence of tension is detected, this evidence is robust and easy to interpret. Assuming a flat Lambda cold dark matter (ΛCDM) cosmological model, we find that there is a modest 2.2σ tension between the Dark Energy Survey (DES) Year 1 results and the Planck measurements of the cosmic microwave background. This tension is driven by the difference between the amount of structure observed in the late-time Universe and that predicted from fitting the Planck data, and appears to be unrelated to the tension between Planck and local estimates of the Hubble rate. In particular, combining DES, baryon acoustic oscillations, big bang nucleosynthesis, and supernovae measurements recover a Hubble constant and sound horizon consistent with Planck, and in tension with local distance–ladder measurements. If the tension between these various data sets persists, it is likely that reconciling all current data will require breaking the flat ΛCDM model in at least two different ways: one involving new physics in the early Universe, and one involving new late-time Universe physics.

scholarly journals Nuclear Constraints on the Age of the Universe

1983 ◽  
Vol 6 ◽  
pp. 241-253 ◽  
Author(s):  
David N. Schramm
Keyword(s):  
Cosmological Constant ◽  
Nuclear Physics ◽  
Big Bang ◽  
Distance Scale ◽  
The Other ◽  
Single Measurement ◽  
Age Of The Universe ◽  
The Big Bang ◽  
The Universe ◽  
Fair Degree

In this paper a review will be made of how one can use nuclear physics to put rather stringent limits on the age of the universe and thus the cosmic distance scale. As the other papers in this session have demonstrated there is some disagreement on the distance scale and thus the limits on the age of the universe (if the cosmological constant Λ = 0.) However, the disagreement is only over the last factor of 2, the basic timescale seems to really be remarkably well agreed upon. The universe is billions of years old - not thousands, not quintillions but billions of years. That our universe has a finite age is philosophically intriguing. That we can estimate that age to a fair degree of accuracy is truly impressive.No single measurement of the time since the Big Bang gives a specific, unambiguous age. Fortunately, we have at our disposal several methods that together fix the age with surprising precision.

scholarly journals Anisotropic quantum cosmology with minimally coupled scalar field

2019 ◽  
Vol 34 (34) ◽  
pp. 1950283 ◽  
Author(s):  
Saumya Ghosh ◽  
Sunandan Gangopadhyay ◽  
Prasanta K. Panigrahi
Keyword(s):  
Scalar Field ◽  
Wave Packet ◽  
Quantum Cosmology ◽  
Hamiltonian Formalism ◽  
Big Bang ◽  
Type I ◽  
The Big Bang ◽  
The Universe ◽  
Big Bang Singularity

In this paper, we perform the Wheeler–DeWitt quantization for Bianchi type I anisotropic cosmological model in the presence of a scalar field minimally coupled to the Einstein–Hilbert gravity theory. We also consider the cosmological (perfect) fluid to construct the matter sector of the model whose dynamics plays the role of time. After obtaining the Wheeler–DeWitt equation from the Hamiltonian formalism, we then define the self-adjointness relations properly. Doing that, we proceed to get a solution for the Wheeler–DeWitt equation and construct a well-behaved wave function for the universe. The wave packet is next constructed from a superposition of the wave functions with different energy eigenvalues together with a suitable weight factor which renders the norm of the wave packet finite. It is then concluded that the Big-Bang singularity can be removed in the context of quantum cosmology.

Could God Have Made the Big Bang? (On Theistic Counterfactuals)

Dialogue ◽  
1994 ◽  
Vol 33 (1) ◽  
pp. 3-20
Author(s):  
Duncan Macintosh
Keyword(s):  
Big Bang ◽  
Will Emit ◽  
Initial States ◽  
Ex Nihilo ◽  
The Big Bang ◽  
The Universe ◽  
Big Bang Singularity ◽  
Infinite Temperature ◽  
P 53 ◽  
Better Than

That the universe began in a big bang is often believed by theists to confirm divine creation ex nihilo. But Quentin Smith claims that it means God must not exist. For if he does, there is an earliest state E of the universe. God made E. E is ensured either to contain animate creatures or to lead to an animate state. For God would know that an animate universe is better than an inanimate one, and that even a minimally morally good being would be obliged to create one if he could. And God, being at least minimally mor-ally good, and all-powerful, would be able and inclined to ensure the existence of one (p. 53). But science says that E is inanimate since the big bang singularity (E) involves the life-hostile conditions of infinite temperature, curvature and density; also that it is inherently unpredictable and lawless so that there is no guarantee it will emit particles that will evolve into an animate state. Thus £ is not ensured to lead to an animate state (p. 53), and thus God could not have made E. So, God does not exist (p. 54). Smith: “There are countless logically possible initial states of the universe that lead by a natural and law-like evolution to animate states and if God had created the universe he would have selected one of these” (p. 58).

scholarly journals The Hot Big Bang and Beyond

1996 ◽  
Vol 168 ◽  
pp. 301-320
Author(s):  
Michael S. Turner
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Hubble Space Telescope ◽  
Hubble Constant ◽  
Big Bang ◽  
Small Admixture ◽  
Matter Theory ◽  
Density Perturbations ◽  
The Big Bang ◽  
The Universe

The hot big-bang cosmology provides a reliable accounting of the Universe from about 10−2sec after the bang until the present, as well as a robust framework for speculating back to times as early as 10−43sec. Cosmology faces a number of important challenges; foremost among them are determining the quantity and composition of matter in the Universe and developing a detailed and coherent picture of how structure (galaxies, clusters of galaxies, superclusters, voids, great walls, and so on) developed. At present there is a working hypothesis—cold dark matter—which is based upon inflation and which, if correct, would extend the big bang model back to 10−32sec and cast important light on the unification of the forces. Many experiments and observations, from CBR anisotropy experiments to Hubble Space Telescope observations to experiments at Fermilab and CERN, are now putting the cold dark matter theory to the test. At present it appears that the theory is viable only if the Hubble constant is smaller than current measurements indicate (around 30 km s−1Mpc−1), or if the theory is modified slightly, e.g., by the addition of a cosmological constant, a small admixture of hot dark matter (5 eV “worth of neutrinos”), more relativistic particles, or a tilted spectrum of density perturbations.

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