scholarly journals The Mach's Principle and Large-scale Modification of Newtonian Gravitation as Alternative Approach to Cold Dark Matter and Dark Energy

2021 ◽  
Author(s):  
Nelson Falcon
Keyword(s):  
Dark Energy ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Additional Term ◽  
Mach's Principle ◽  
Mach’S Principle ◽  
Missing Mass ◽  
Birkhoff Theorem ◽  
Newtonian Gravitation ◽  
Alternative Approach

We take a heterodox approach to the ΛFRW Cosmology starting from the modification of Newtonian gravity by explicitly incorporating Mach's Principle through an additional term a great scale in the gravitation. The results show that at the after of the matter-radiation decoupling, the distribution of matter at scales greater than 10Mpc contributes with an inverse Yukawa-like field, which verifies the observations: resulting null in the inner solar system, weakly attractive in ranges of interstellar comoving distances, very attractive in comoving distance ranges comparable to the clusters of galaxies, and repulsive in cosmic scales. This additional term explains dark energy, removes the incompatibility between the density of matter and the flatness of the universe; and also allows the theoretical deduction of the Hubble-Lemaitre Law. Additionally, Birkhoff Theorem, Virial Theorem, the missing mass of Zwicky, the BAO, gravitational redshift are discussed. It is concluded that the dark energy and the missing mass can be approached with the usual physics if a classical, large-scale modification of the Inverse Square Law.

scholarly journals Observational constraints of a new unified dark fluid and the H0 tension

2019 ◽  
Vol 490 (2) ◽  
pp. 2071-2085 ◽  
Author(s):  
Weiqiang Yang ◽  
Supriya Pan ◽  
Andronikos Paliathanasis ◽  
Subir Ghosh ◽  
Yabo Wu
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Early Time ◽  
Observational Constraints ◽  
Minimal Extension ◽  
Energy Evolution ◽  
The Universe ◽  
Different Sources

ABSTRACT Unified cosmological models have received a lot of attention in astrophysics community for explaining both the dark matter and dark energy evolution. The Chaplygin cosmologies, a well-known name in this group have been investigated matched with observations from different sources. Obviously, Chaplygin cosmologies have to obey restrictions in order to be consistent with the observational data. As a consequence, alternative unified models, differing from Chaplygin model, are of special interest. In the present work, we consider a specific example of such a unified cosmological model, that is quantified by only a single parameter μ, that can be considered as a minimal extension of the Λ-cold dark matter cosmology. We investigate its observational boundaries together with an analysis of the universe at large scale. Our study shows that at early time the model behaves like a dust, and as time evolves, it mimics a dark energy fluid depicting a clear transition from the early decelerating phase to the late cosmic accelerating phase. Finally, the model approaches the cosmological constant boundary in an asymptotic manner. We remark that for the present unified model, the estimations of H0 are slightly higher than its local estimation and thus alleviating the H0 tension.

scholarly journals COSMOLOGY AND LOCAL PHYSICS

2002 ◽  
Vol 17 (20) ◽  
pp. 2667-2671 ◽  
Author(s):  
GEORGE F. R. ELLIS
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Mach's Principle ◽  
Mach’S Principle ◽  
The Universe

This article considers the two-way relationship between local physics and the large scale structure of the universe - in particular considering Olber's paradox, Mach's principle, and the various arrows of time. Thus the focus is various ways in which local physics is influenced by the universe itself.

scholarly journals RELATIONAL STATISTICAL SPACE-TIME FOR COSMOLOGICAL SCALES

Metaphysics ◽  
2020 ◽  
pp. 62-70
Author(s):  
V. V Aristov
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Statistical Approach ◽  
Theoretical Models ◽  
Space Time ◽  
Dynamic Equations ◽  
Mach's Principle ◽  
Mach’S Principle ◽  
High Speeds ◽  
Statistical Space

The relational statistical approach is used in the study of phenomena of macroscopic cosmological scales. In fact, a variant of the generalized Mach’s principle is developing. Theoretical models of Dark matter as well as Dark energy without introducing additional particles and forces are discussed. Changes in the ordinary kinematic and dynamic equations for ultra-ultra-high speeds are considered. Some new effects are predicted at such energy scales.

scholarly journals A common explanation of the Hubble tension and anomalous cold spots in the CMB

2020 ◽  
Vol 499 (1) ◽  
pp. 320-333
Author(s):  
A Kovács ◽  
R Beck ◽  
I Szapudi ◽  
I Csabai ◽  
G Rácz ◽  
...  
Keyword(s):  
Dark Energy ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Hubble Constant ◽  
Cold Spot ◽  
Microwave Background ◽  
Spot Area ◽  
Dark Energy Component ◽  
Repeated Observation ◽  
Temperature Maps

ABSTRACT The standard cosmological paradigm narrates a reassuring story of a universe currently dominated by an enigmatic dark energy component. Disquietingly, its universal explaining power has recently been challenged by, above all, the ∼4σ tension in the values of the Hubble constant. Another, less studied anomaly is the repeated observation of integrated Sachs–Wolfe (ISW) imprints ∼5× stronger than expected in the Lambda cold dark matter (ΛCDM) model from $R_{\rm v}\gtrsim 100\,\rm {\mathit{ h}^{-1}Mpc }$ superstructures. Here, we show that the inhomogeneous AvERA (Average Expansion Rate Approximation) model of emerging curvature is capable of telling a plausible albeit radically different story that explains both observational anomalies without dark energy. We demonstrate that while stacked imprints of $R_{\rm v}\gtrsim 100\,\rm {\mathit{ h}^{-1}Mpc }$ supervoids in cosmic microwave background (CMB) temperature maps can discriminate between the AvERA and ΛCDM models, their characteristic differences may remain hidden using alternative void definitions and stacking methodologies. Testing the extremes, we then also show that the CMB Cold Spot can plausibly be explained in the AvERA model as an ISW imprint. The coldest spot in the AvERA map is aligned with multiple low-z supervoids with $R_{\rm v}\gtrsim 100\,\rm {\mathit{ h}^{-1}Mpc }$ and central underdensity δ0 ≈ −0.3, resembling the observed large-scale galaxy density field in the Cold Spot area. We hence conclude that the anomalous imprint of supervoids may well be the canary in the coal mine, and existing observational evidence for dark energy should be reinterpreted to further test alternative models.

scholarly journals The BAHAMAS project: effects of dynamical dark energy on large-scale structure

2020 ◽  
Vol 498 (2) ◽  
pp. 1576-1592 ◽  
Author(s):  
Simon Pfeifer ◽  
Ian G McCarthy ◽  
Sam G Stafford ◽  
Shaun T Brown ◽  
Andreea S Font ◽  
...  
Keyword(s):  
Dark Energy ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Large Scale Structure ◽  
Scale Structure ◽  
The Bahamas ◽  
Wide Range ◽  
Hydrodynamical Simulations ◽  
The Impact ◽  
Dynamical Dark Energy

ABSTRACT In this work, we consider the impact of spatially uniform but time-varying dark energy (or ‘dynamical dark energy’, DDE) on large-scale structure in a spatially flat universe, using large cosmological hydrodynamical simulations that form part of the BAHAMAS project. As DDE changes the expansion history of the universe, it impacts the growth of structure. We explore variations in DDE that are constrained to be consistent with the cosmic microwave background. We find that DDE can affect the clustering of matter and haloes at the $\sim 10{{\ \rm per\ cent}}$ level (suppressing it for so-called freezing models, while enhancing it for thawing models), which should be distinguishable with upcoming large-scale structure surveys. DDE cosmologies can also enhance or suppress the halo mass function (with respect to Lambda cold dark matter) over a wide range of halo masses. The internal properties of haloes are minimally affected by changes in DDE, however. Finally, we show that the impact of baryons and associated feedback processes is largely independent of the change in cosmology and that these processes can be modelled separately to typically better than a few per cent accuracy.

scholarly journals Is dark energy – an alias of cosmic rotational kinetic energy?

2016 ◽  
Vol 4 (2) ◽  
pp. 90
Author(s):  
Satya Seshavatharam UV ◽  
Lakshminarayana S
Keyword(s):  
Dark Energy ◽  
Kinetic Energy ◽  
Planck Scale ◽  
Mach's Principle ◽  
Mach’S Principle

Considering Planck scale and Mach’s principle, theoretically it is possible to show that magnitude of the currently believed dark energy is equal to the magnitude of current cosmic rotational kinetic energy.

scholarly journals Shell-crossing in a ΛCDM Universe

2020 ◽  
Vol 501 (1) ◽  
pp. L71-L75
Author(s):  
Cornelius Rampf ◽  
Oliver Hahn
Keyword(s):  
Dark Matter ◽  
Perturbation Theory ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Three Dimensional ◽  
Random Initial Data ◽  
Recursion Relations ◽  
Indispensable Tool ◽  
First Time ◽  
Very High

ABSTRACT Perturbation theory is an indispensable tool for studying the cosmic large-scale structure, and establishing its limits is therefore of utmost importance. One crucial limitation of perturbation theory is shell-crossing, which is the instance when cold-dark-matter trajectories intersect for the first time. We investigate Lagrangian perturbation theory (LPT) at very high orders in the vicinity of the first shell-crossing for random initial data in a realistic three-dimensional Universe. For this, we have numerically implemented the all-order recursion relations for the matter trajectories, from which the convergence of the LPT series at shell-crossing is established. Convergence studies performed at large orders reveal the nature of the convergence-limiting singularities. These singularities are not the well-known density singularities at shell-crossing but occur at later times when LPT already ceased to provide physically meaningful results.

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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