scholarly journals Formation of Elements and Compounds in Space in Early Universe

2016 ◽  
Vol 8 (6) ◽  
pp. 86
Author(s):  
Abdul L. Bhuiyan
Keyword(s):  
Dark Matter ◽  
High Temperature ◽  
Early Universe ◽  
High Speed ◽  
Virtual State ◽  
Speed Of Light ◽  
Electron Positron ◽  
Living Organisms ◽  
The Universe

<p class="1Body">At the end of the period of contraction of the universe, all objects transform into gravity particles such as photons and electron- positron pairs which exist in virtual state in spacetime at an extremely high temperature. These particles move with extremely high speed comparable to the speed of light. As the early universe starts cooling, the speed of the particles starts to decrease when photons and electron- positron pairs move out of spacetime and appear as real particles. As the temperature continues to fall due to cooling, the electron- positron pairs start forming quarks (u and d) while simultaneously the energy of photons transform into dark matter. The u quarks and d quarks then continue to form nuclei of different elements including radio elements. Simultaneously, the lighter elements such as hydrogen, nitrogen, carbon, oxygen, phosphorus, etc. form the precursors to DNAs and RNAs of living organisms.</p>

scholarly journals Displaced new physics at colliders and the early universe before its first second

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Lorenzo Calibbi ◽  
Francesco D’Eramo ◽  
Sam Junius ◽  
Laura Lopez-Honorez ◽  
Alberto Mariotti
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Upper Bound ◽  
New Physics ◽  
Early History ◽  
Relic Density ◽  
History Of ◽  
Indirect Information ◽  
The Universe

Abstract Displaced vertices at colliders, arising from the production and decay of long-lived particles, probe dark matter candidates produced via freeze-in. If one assumes a standard cosmological history, these decays happen inside the detector only if the dark matter is very light because of the relic density constraint. Here, we argue how displaced events could very well point to freeze-in within a non-standard early universe history. Focusing on the cosmology of inflationary reheating, we explore the interplay between the reheating temperature and collider signatures for minimal freeze-in scenarios. Observing displaced events at the LHC would allow to set an upper bound on the reheating temperature and, in general, to gather indirect information on the early history of the universe.

Most of the Universe is Missing!

2019 ◽  
pp. 64-72
Author(s):  
Nicholas Mee
Keyword(s):  
Dark Matter ◽  
Galaxy Clusters ◽  
Early Universe ◽  
The World ◽  
Unknown Form ◽  
Theory Of Gravity ◽  
Stable Particles ◽  
The Universe

Most of the matter in the universe exists in an unknown form called dark matter. All estimates of the mass of galaxies and galaxy clusters suggest they contain far more matter than is visible to us in the form of stars. Conventional explanations, such as the existence of large quantities of burnt-out stars known as MACHOs or dark gas clouds, have been ruled out. The most popular explanation is that dark matter consists of vast quantities of hypothetical stable particles known as WIMPs that were produced in vast quantities in the very early universe. Many laboratories around the world are searching for signs of these particles. These include the Italian Gran Sasso laboratory running the XENON100 experiment. Some theorists have suggested the evidence for dark matter would disappear if we had a better theory of gravity. Analysis of the Bullet Cluster indicates such proposals will not work.

scholarly journals Impact of neutrino properties and dark matter on the primordial Lithium production

2019 ◽  
Vol 28 (08) ◽  
pp. 1950065 ◽  
Author(s):  
Tahani R. Makki ◽  
Mounib F. El Eid ◽  
Grant J. Mathews
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Nuclear Physics ◽  
Big Bang ◽  
Light Elements ◽  
Big Bang Nucleosynthesis ◽  
Chemical Potentials ◽  
The Creation ◽  
The Universe

The light elements and their isotopes were produced during standard big bang nucleosynthesis (SBBN) during the first minutes after the creation of the universe. Comparing the calculated abundances of these light species with observed abundances, it appears that all species match very well except for lithium (7Li) which is overproduced by the SBBN. This discrepancy is rather challenging for several reasons to be considered on astrophysical and on nuclear physics ground, or by invoking nonstandard assumptions which are the focus of this paper. In particular, we consider a variation of the chemical potentials of the neutrinos and their temperature. In addition, we investigated the effect of dark matter on 7Li production. We argue that including nonstandard assumptions can lead to a significant reduction of the 7Li abundance compared to that of SBBN. This aspect of lithium production in the early universe may help to resolve the outstanding cosmological lithium problem.

scholarly journals Indirect effects of dark matter

2019 ◽  
Vol 28 (13) ◽  
pp. 1941011 ◽  
Author(s):  
K. M. Belotsky ◽  
E. A. Esipova ◽  
A. Kh. Kamaletdinov ◽  
E. S. Shlepkina ◽  
M. L. Solovyov
Keyword(s):  
Dark Matter ◽  
Indirect Effects ◽  
Large Scale ◽  
Gamma Ray ◽  
Space Distribution ◽  
Stable Form ◽  
Final State ◽  
Electron Positron ◽  
Text Mode ◽  
The Universe

Here, we briefly review possible indirect effects of dark matter (DM) of the universe. It includes effects in cosmic rays (CR): first of all, the positron excess at [Formula: see text]500[Formula: see text]GeV and possible electron–positron excess at 1–1.5[Formula: see text]TeV. We tell that the main and least model-dependent constraint on such possible interpretation of CR effects goes from gamma-ray background. Even ordinary [Formula: see text] mode of DM decay or annihilation produces prompt photons (FSR) so much that it leads to contradiction with data on cosmic gamma-rays. We present our attempts to possibly avoid gamma-ray constraint. They concern with peculiarities of both space distribution of DM and their physics. The latter involves complications of decay/annihilation modes of DM, modifications of Lagrangian of DM-ordinary matter interaction and inclusion of mode with identical fermions in final state. In this way, no possibilities to suppress were found except, possibly, the mode with identical fermions. While the case of spatial distribution variation allows achieving consistency between different data. Also, we consider stable form of DM which can interact with baryons. We show which constraint such DM candidate can get from the damping effect in plasma during large-scale structure (LSS) formation in comparison with other existing constraints.

scholarly journals The Lyman-α forest as a diagnostic of the nature of the dark matter

2019 ◽  
Vol 489 (3) ◽  
pp. 3456-3471 ◽  
Author(s):  
Antonella Garzilli ◽  
Andrii Magalich ◽  
Tom Theuns ◽  
Carlos S Frenk ◽  
Christoph Weniger ◽  
...  
Keyword(s):  
Dark Matter ◽  
High Temperature ◽  
High Resolution ◽  
Power Spectrum ◽  
Early Universe ◽  
Thermal Effects ◽  
Cold Dark Matter ◽  
Sterile Neutrinos ◽  
Hydrodynamic Simulations ◽  
Very High

ABSTRACT The observed Lyman-α flux power spectrum (FPS) is suppressed on scales below ${\sim} ~ 30\, {\rm km\, s}^{-1}$. This cut-off could be due to the high temperature, T0, and pressure, p0, of the absorbing gas or, alternatively, it could reflect the free streaming of dark matter particles in the early universe. We perform a set of very high resolution cosmological hydrodynamic simulations in which we vary T0, p0, and the amplitude of the dark matter free streaming, and compare the FPS of mock spectra to the data. We show that the location of the dark matter free-streaming cut-off scales differently with redshift than the cut-off produced by thermal effects and is more pronounced at higher redshift. We, therefore, focus on a comparison to the observed FPS at z > 5. We demonstrate that the FPS cut-off can be fit assuming cold dark matter, but it can be equally well fit assuming that the dark matter consists of ∼7 keV sterile neutrinos in which case the cut-off is due primarily to the dark matter free streaming.

scholarly journals ACCELERATION AND DECELERATION IN THE CURVATURE-INDUCED PHANTOM MODEL OF THE LATE AND FUTURE UNIVERSE: COSMIC COLLAPSE AND ITS QUANTUM ESCAPE

2009 ◽  
Vol 18 (05) ◽  
pp. 865-887
Author(s):  
S. K. SRIVASTAVA ◽  
J. DUTTA
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Quantum Gravity ◽  
Cosmological Constant ◽  
Early Universe ◽  
High Energy ◽  
High Energy Density ◽  
Energy Models ◽  
Acceleration And Deceleration ◽  
The Universe

In this paper, the cosmology of the late and future universe is obtained from f(R) gravity with nonlinear curvature terms R2 and R3 (R is the Ricci scalar curvature). It is different from f(R) dark energy models where nonlinear curvature terms are taken as a gravitational alternative to dark energy. In the present model, neither linear nor nonlinear curvature terms are taken as dark energy. Rather, dark energy terms are induced by curvature terms and appear in the Friedmann equation derived from f(R) gravitational equations. This approach has an advantage over f(R) dark energy models in three ways: (i) results are consistent with WMAP observations, (ii) dark matter is produced from the gravitational sector and (iii) the universe expands as ~ t2/3 during dominance of the curvature-induced dark matter, which is consistent with the standard cosmology. Curvature-induced dark energy mimics phantom and causes late acceleration. It is found that transition from matter-driven deceleration to acceleration takes place at the redshift 0.36 at time 0.59 t0 (t0 is the present age of the universe). Different phases of this model, including acceleration and deceleration during the phantom phase, are investigated. It is found that expansion of the universe will stop at the age of 3.87 t0 + 694.4 kyr. After this epoch, the universe will contract and collapse by the time of 336.87 t0 + 694.4 kyr. Further, it is shown that cosmic collapse obtained from classical mechanics can be avoided by making quantum gravity corrections relevant near the collapse time due to extremely high energy density and large curvature analogous to the state of the very early universe. Interestingly, the cosmological constant is also induced here; it is extremely small in the classical domain but becomes very high in the quantum domain. This result explains the largeness of the cosmological constant in the early universe due to quantum gravity effects during this era and its very low value in the present universe due to negligible quantum effect in the late universe.

scholarly journals SUPERHEAVY PARTICLES IN FRIEDMANN COSMOLOGY AND THE DARK MATTER PROBLEM

2002 ◽  
Vol 11 (03) ◽  
pp. 433-436 ◽  
Author(s):  
A. A. GRIB ◽  
YU. V. PAVLOV
Keyword(s):  
Dark Matter ◽  
Gravitational Field ◽  
Early Universe ◽  
Particle Creation ◽  
Baryon Number ◽  
Matter Density ◽  
Friedmann Model ◽  
Dark Matter Density ◽  
The Universe

The model of creation of observable particles and particles of the dark matter, considered to be superheavy particles, due to particle creation by the gravitational field of the Friedmann model of the early Universe is given. Estimates on the parameters of the model leading to observable values of the baryon number of the Universe and the dark matter density are made.

scholarly journals Dual Cosmic Horizon Radius of Spacetime Curvature of a Multi-Path Connected Cosmic Topology

2020 ◽  
Author(s):  
Mohammed B. Al-Fadhli
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
High Speed ◽  
Initial Conditions ◽  
Large Angle ◽  
Big Bang ◽  
Accelerated Expansion ◽  
Horizon Radius ◽  
Spacetime Curvature ◽  
The Universe

The necessity of the dark energy and dark matter in the present universe could be a consequence of the antimatter elimination assumption in the early universe. In this research, I derive a new model to obtain the cosmic horizon radius and the potential cosmic topology utilising a new construal of space geometry inspired by large-angle correlations of the cosmic microwave background (CMB). A version of the Big Bounce theory is utilised to avoid the Big Bang singularity and inflationary constraints, and to tune the initial conditions of the curvature density. The mathematical derivation of a positively curved universe governed by only gravity revealed two cosmic horizon solutions. Although the positive horizon is conventionally associated with the evolution of the matter universe, the negative horizon solution could imply additional evolution in the opposite direction. This possibly suggests that the matter and antimatter could be evolving in opposite directions as distinct sides of the universe, as in the visualised Sloan Digital Sky Survey. The cosmic horizon radius is found to be accountable for the universal space curvature. By implementing this model, we find a decelerated stage of expansion during the first 10 Gyr, which is followed by a second stage of an accelerated expansion; potentially matching the tension in Hubble parameter measurements. In addition, the model predicts a final time-reversal stage of spatial contraction leading to the Big Crunch of a cyclic universe. The predicted density is 1.14. Other predictions are (1) a calculable flow rate of the matter side towards the antimatter side at the accelerated stage; conceivably explaining the dark flow observation, (2) a time-dependent spacetime curvature over horizon evolution, which could influence the galactic rotational speed; possibly explaining the high speed of stars, and (3) evolvable spacetime internal voids at the accelerated stage, which could contribute in continuously increasing the matter and antimatter densities elsewhere in both sides respectively. These findings may indicate the existence of the antimatter as a distinct side, which influences the evolution of the universe instead of the dark energy or dark matter.

scholarly journals Evolution of Primordial Dark Matter Planets in the Early Universe

2020 ◽  
Author(s):  
Arun Kenath ◽  
Kiren O. V. ◽  
Sivaram C
Keyword(s):  
Dark Matter ◽  
Neutron Stars ◽  
Early Universe ◽  
Critical Thickness ◽  
Nuclear Reactions ◽  
Compact Objects ◽  
X Ray ◽  
Primordial Planets ◽  
The Universe ◽  
Observational Signature

In a recent paper we had discussed possibility of DM at high redshifts forming primordial planets composed entirely of DM to be one of the reasons for not detecting DM (as the flux of ambient DM particles would be consequently reduced). In this paper we discuss the evolution of these DM objects as the universe expands. As universe expands there will be accretion of DM, Helium and Hydrogen layers (discussed in detail) on these objects. As they accumulate more and more mass, the layers get heated up leading to nuclear reactions which burn H and He when a critical thickness is reached. In the case of heavier masses of these DM objects, matter can be ejected explosively. It is found that the time scale of ejection is smaller than those from other compact objects like neutron stars (that lead to x-ray bursts). These flashes of energy could be a possible observational signature for these dense DM objects.

scholarly journals Dark Matter and Dark Energy in the Universe

2018 ◽  
Vol 14 (1) ◽  
pp. 5292-5295
Author(s):  
Yuanjie Li ◽  
Lihong Zhang ◽  
Peng Dong
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Dark Energy ◽  
Early Universe ◽  
Left Behind ◽  
Time Quantum ◽  
The Universe

This paper points out that not only all quantum-ghost puzzles occur in the Time Quantum Worm Hole, but also the dark matter in the universe is hidden in it. Dark energy is the contribution of the Planck black hole left behind by the early universe.

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