A recharged debate over the speed of the expansion of the universe could lead to new physics

Science ◽  
2017 ◽  
Author(s):  
Joshua Sokol
Keyword(s):  
New Physics ◽  
Expansion Of The Universe ◽  
The Universe

scholarly journals ADDRESSING THE CRISIS IN FUNDAMENTAL PHYSICS

2007 ◽  
Vol 16 (12a) ◽  
pp. 1947-1952
Author(s):  
CHRISTOPHER W. STUBBS
Keyword(s):  
Dark Energy ◽  
State Parameter ◽  
New Physics ◽  
Fundamental Physics ◽  
Accelerating Expansion ◽  
Cosmological Observations ◽  
Real Risk ◽  
Expansion Of The Universe ◽  
The One ◽  
The Universe

The observation that the expansion of the Universe is proceeding at an ever-increasing rate, i.e. the "dark energy" problem, constitutes a crisis in fundamental physics that is as profound as the one that preceded the advent of quantum mechanics. Cosmological observations currently favor a dark energy equation-of-state parameter w = P/ρ = -1. Awkwardly, this is the value that has the least ability to discriminate between alternatives for the physics that produces the observed accelerating expansion. If this result persists we therefore run a very real risk of stagnation in our attempt to better understand the nature of this new physics, unless we uncover another piece of the dark energy puzzle. I argue that precision fundamental measurements in space have an important role in addressing this crisis.

scholarly journals REINVENTING SPACETIME ON A DYNAMICAL HYPERSURFACE

2006 ◽  
Vol 21 (12) ◽  
pp. 947-959 ◽  
Author(s):  
J. PONCE DE LEON
Keyword(s):  
Extra Dimension ◽  
New Physics ◽  
Accelerated Expansion ◽  
Effective Equation ◽  
Higher Dimensional ◽  
Internal Contradiction ◽  
Frw Model ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Kaluza Klein

In braneworld models, Spacetime-Matter and other Kaluza–Klein theories, our spacetime is devised as a four-dimensional hypersurface orthogonal to the extra dimension in a five-dimensional bulk. We show that the FRW line element can be "reinvented" on a dynamical four-dimensional hypersurface, which is not orthogonal to the extra dimension, without any internal contradiction. This hypersurface is selected by the requirement of continuity of the metric and depends explicitly on the evolution of the extra dimension. The main difference between the "conventional" FRW, on an orthogonal hypersurface, and the new one is that the latter contains higher-dimensional modifications to the regular matter density and pressure in 4D. We compare the evolution of the spacetime in these two interpretations and find that a wealth of "new" physics can be derived from a five-dimensional metric if it is interpreted on a dynamical (non-orthogonal) 4D hypersurface. In particular, in the context of a well-known cosmological metric in 5D, we construct a FRW model which is consistent with the late accelerated expansion of the universe, while fitting simultaneously the observational data for the deceleration parameter. The model predicts an effective equation of state for the universe, which is consistent with observations.

scholarly journals Einstein, Planck and Vera Rubin: Relevant Encounters Between the Cosmological and the Quantum Worlds

2021 ◽  
Vol 8 ◽  
Author(s):  
Paolo Salucci ◽  
Giampiero Esposito ◽  
Gaetano Lambiase ◽  
Emmanuele Battista ◽  
Micol Benetti ◽  
...  
Keyword(s):  
Dark Matter ◽  
Quantum Physics ◽  
Dark Matter Particle ◽  
High Energy ◽  
New Physics ◽  
Compact Objects ◽  
Accelerated Expansion ◽  
Special Topic ◽  
Expansion Of The Universe ◽  
The Universe

In Cosmology and in Fundamental Physics there is a crucial question like: where the elusive substance that we call Dark Matter is hidden in the Universe and what is it made of? that, even after 40 years from the Vera Rubin seminal discovery [1] does not have a proper answer. Actually, the more we have investigated, the more this issue has become strongly entangled with aspects that go beyond the established Quantum Physics, the Standard Model of Elementary particles and the General Relativity and related to processes like the Inflation, the accelerated expansion of the Universe and High Energy Phenomena around compact objects. Even Quantum Gravity and very exotic Dark Matter particle candidates may play a role in framing the Dark Matter mystery that seems to be accomplice of new unknown Physics. Observations and experiments have clearly indicated that the above phenomenon cannot be considered as already theoretically framed, as hoped for decades. The Special Topic to which this review belongs wants to penetrate this newly realized mystery from different angles, including that of a contamination of different fields of Physics apparently unrelated. We show with the works of this ST that this contamination is able to guide us into the required new Physics. This review wants to provide a good number of these “paths or contamination” beyond/among the three worlds above; in most of the cases, the results presented here open a direct link with the multi-scale dark matter phenomenon, enlightening some of its important aspects. Also in the remaining cases, possible interesting contacts emerges. Finally, a very complete and accurate bibliography is provided to help the reader in navigating all these issues.

scholarly journals The expansion of the Universe may be an illusion created by Compton scattering of free electrons

2021 ◽  
Author(s):  
GuanFeng Cheng
Keyword(s):  
Compton Scattering ◽  
New Physics ◽  
Precision Measurements ◽  
Free Electrons ◽  
Expansion Factor ◽  
Distant Galaxy ◽  
Cosmological Redshift ◽  
Exponential Expansion ◽  
Expansion Of The Universe ◽  
The Universe

Abstract The high-precision measurements of the Hubble parameter make the theory of cosmic expansion more and more confusing, which bolster the idea that new physics may be needed to explain the mismatch. The cosmological redshift may not only be related to distance but also to other factors. The expansion of the Universe may be just an illusion. The Compton effect of free electrons and low energy photons has been observed in the laboratory. This article proposes a theory: Free electron Compton scattering (FEC) produce the illusion of the Universe exponential expansion: FEC causes photons to redshift (FEC redshift), and the photon beam expands along the propagation direction, that is, the redshift factor is (1 + z); the beam length stretch factor (time dilation of the supernova curve) is (1 + z); the expansion factor of the beam volume is (1 + z)3, and FEC will not be blurred Distant galaxy. The reason for rejecting the “tired light” does not hold in FEC.

scholarly journals Theory that Predicts and Explains Data about Elementary Particles, Dark Matter, Early Galaxies, and the Cosmos

2020 ◽  
Author(s):  
Thomas J. Buckholtz
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
New Physics ◽  
Elementary Particles ◽  
Harmonic Oscillators ◽  
Ordinary Matter ◽  
Expansion Of The Universe ◽  
Early Galaxies ◽  
The Universe

We develop and apply new physics theory. The theory suggests specific unfound elementary particles. The theory suggests specific constituents of dark matter. We apply those results. We explain ratios of dark matter amounts to ordinary matter amounts. We suggest details about galaxy formation. We suggest details about inflation. We suggest aspects regarding changes in the rate of expansion of the universe. The theory points to relationships between masses of elementary particles. We show a relationship between the strength of electromagnetism and the strength of gravity. The mathematics basis for matching known and suggesting new elementary particles extends mathematics for harmonic oscillators.

Black Hole Universe: a grand cosmic recycler and Big Bang generator?

2019 ◽  
Author(s):  
Matheus Pereira Lobo
Keyword(s):  
Black Hole ◽  
Big Bang ◽  
Subsequent Increase ◽  
Expansion Of The Universe ◽  
The Universe

We propose the discussion of a highly speculative idea for the scenario where black hole collisions and their subsequent increase in sizes exceed the expansion of the universe.

Cosmological constant

2018 ◽  
Author(s):  
Michael Kachelriess
Keyword(s):  
Dark Energy ◽  
Cosmological Constant ◽  
Accelerated Expansion ◽  
Vacuum Fluctuations ◽  
Present Epoch ◽  
Modify Gravity ◽  
Expansion Of The Universe ◽  
The Universe

The contribution of vacuum fluctuations to the cosmological constant is reconsidered studying the dependence on the used regularisation scheme. Then alternative explanations for the observed accelerated expansion of the universe in the present epoch are introduced which either modify gravity or add a new component of matter, dubbed dark energy. The chapter closes with some comments on attempts to quantise gravity.

scholarly journals Mixed fluid cosmological model in f(R, T) gravity

2020 ◽  
Vol 98 (11) ◽  
pp. 1015-1022 ◽  
Author(s):  
Parbati Sahoo ◽  
Barkha Taori ◽  
K.L. Mahanta
Keyword(s):  
Cosmological Model ◽  
Bianchi Type ◽  
Type I ◽  
Time Varying ◽  
Eos Parameter ◽  
Barotropic Fluid ◽  
Rotationally Symmetric ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Mixed Fluid

We construct a locally rotationally symmetric (LRS) Bianchi type-I cosmological model in f(R, T) theory of gravity when the source of gravitation is a mixture of barotropic fluid and dark energy (DE) by employing a time-varying deceleration parameter. We observe through the behavior of the state finder parameters (r, s) that our model begins from the Einstein static era and goes to ΛCDM era. The equation of state (EOS) parameter (ωd) for DE varies from the phantom (ω < –1) phase to quintessence (ω > –1) phase, which is consistent with observational results. It is found that the discussed model can reproduce the current accelerating phase of the expansion of the universe.

scholarly journals Taxonomy of Dark Energy Models

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 163
Author(s):  
Verónica Motta ◽  
Miguel A. García-Aspeitia ◽  
Alberto Hernández-Almada ◽  
Juan Magaña ◽  
Tomás Verdugo
Keyword(s):  
Dark Energy ◽  
Cold Dark Matter ◽  
Accelerated Expansion ◽  
Energy Component ◽  
The Past ◽  
Energy Models ◽  
The Status ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Unknown Component

The accelerated expansion of the Universe is one of the main discoveries of the past decades, indicating the presence of an unknown component: the dark energy. Evidence of its presence is being gathered by a succession of observational experiments with increasing precision in its measurements. However, the most accepted model for explaining the dynamic of our Universe, the so-called Lambda cold dark matter, faces several problems related to the nature of such energy component. This has led to a growing exploration of alternative models attempting to solve those drawbacks. In this review, we briefly summarize the characteristics of a (non-exhaustive) list of dark energy models as well as some of the most used cosmological samples. Next, we discuss how to constrain each model’s parameters using observational data. Finally, we summarize the status of dark energy modeling.

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