scholarly journals Dark Matter - Are They Insulators to Electromagnetic Radiation?

2022 ◽  
Author(s):  
Sayan Bag ◽  
Arijit Bag
Keyword(s):  
Dark Matter ◽  
Electromagnetic Radiation ◽  
Present Article ◽  
Experimental Verification ◽  
Verification Method ◽  
Outstanding Problem ◽  
Normal Matter ◽  
Modern Cosmology ◽  
The Universe ◽  
Peculiar Behavior

The detection of Dark Matter is the greatest outstanding problem in modern cosmology. Several attempts have been taken for this without any remarkable success. To find out a suitable way of detection we need to understand its nature comprehensively. In the present article, a hypothesis is described considering Dark Matter as a normal matter. Its peculiar behavior is explained considering its existence in BEC state in the coolest part of the universe that makes it an electromagnetic insulator. Depending upon this hypothesis an experimental verification method is proposed.

A Tale of Two Infinities

2021 ◽  
Author(s):  
Gianfranco Bertone
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Gravitational Waves ◽  
Direct Detection ◽  
Traditional Approach ◽  
Fundamental Physics ◽  
Modern Cosmology ◽  
Nobel Prize In Physics ◽  
The Universe ◽  
Modern Astronomy

The spectacular advances of modern astronomy have opened our horizon on an unexpected cosmos: a dark, mysterious Universe, populated by enigmatic entities we know very little about, like black holes, or nothing at all, like dark matter and dark energy. In this book, I discuss how the rise of a new discipline dubbed multimessenger astronomy is bringing about a revolution in our understanding of the cosmos, by combining the traditional approach based on the observation of light from celestial objects, with a new one based on other ‘messengers’—such as gravitational waves, neutrinos, and cosmic rays—that carry information from otherwise inaccessible corners of the Universe. Much has been written about the extraordinary potential of this new discipline, since the 2017 Nobel Prize in physics was awarded for the direct detection of gravitational waves. But here I will take a different angle and explore how gravitational waves and other messengers might help us break the stalemate that has been plaguing fundamental physics for four decades, and to consolidate the foundations of modern cosmology.

Dark Matter

2021 ◽  
pp. 66-78
Author(s):  
Gianfranco Bertone
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Gravitational Waves ◽  
Expansion Rate ◽  
The Earth ◽  
Modern Cosmology ◽  
Large Effort ◽  
The Universe

I introduce here the problem of dark energy, a substance that appears to be pushing the Universe to expand ever faster and discuss the large effort currently in place to understand its origin. I describe the surprising recent discovery of a widening crack in the cathedral of modern cosmology arising from the measurement of the expansion rate of the Universe. And I argue that gravitational waves observations can help us to either repair that crack, or to bring down that magnificent building, in case it turns out to be fatally flawed. Before all women and all men. Before animals, plants, archaeans, bacteria. Before the Earth was formed and the stars were lit. Before everything we know, the Universe was immersed in an amorphous and oblivious darkness.

5. Cosmology

2017 ◽  
pp. 58-82
Author(s):  
Timothy Clifton
Keyword(s):  
Dark Matter ◽  
Large Scale ◽  
Gravitational Interaction ◽  
Albert Einstein ◽  
Scientific Discipline ◽  
Normal Matter ◽  
History Of Cosmology ◽  
History Of ◽  
Edwin Hubble ◽  
The Universe

Cosmology began as a scientific discipline at the beginning of the 20th century, with the work of Albert Einstein and Edwin Hubble. Gravitational interaction is fundamental to cosmology, as gravity dominates over all other forces on large-scale distances. ‘Cosmology’ outlines the modern history of cosmology, discussing how studies have provided knowledge on the early Universe and its expansion. The Concordance Model proposes that only c.5 per cent of the energy in the Universe is in the form of normal matter; c.25 per cent is in the form of the gravitationally attractive dark matter; and the remaining c.70 per cent is in the form of the gravitationally repulsive dark energy. But there is still much to learn.

scholarly journals Accelerated expansion of the Universe in the presence of dark matter pressure

2020 ◽  
Vol 98 (2) ◽  
pp. 210-216
Author(s):  
Zeinab Rezaei
Keyword(s):  
Dark Matter ◽  
Equation Of State ◽  
Hubble Parameter ◽  
Energy Equation ◽  
Accelerated Expansion ◽  
Luminosity Distance ◽  
Modern Cosmology ◽  
History Of ◽  
Expansion Of The Universe ◽  
The Universe

Expansion dynamics of the Universe is an important subject in modern cosmology. The dark energy equation of state determines these dynamics so that the Universe is in an accelerating phase. However, dark matter (DM) can also affect the accelerated expansion of the Universe through its equation of state. In the present work, we explore the expansion dynamics of the Universe in the presence of DM pressure. In this regard, applying the DM equation of state from the observational data related to the rotational curves of galaxies, we calculate the evolution of DM density. Moreover, the Hubble parameter, history of scale factor, luminosity distance, and deceleration parameter are studied while the DM pressure is taken into account. Our results verify that the DM pressure leads to higher values of the Hubble parameter at each redshift and the expansion of the Universe grows due to the DM pressure.

scholarly journals КОСМІЧНЕ МІКРОХВИЛЬОВЕ ВИПРОМІНЮВАННЯ І ТЕМНА МАТЕРІЯ

2018 ◽  
pp. 83-101
Author(s):  
Анатолий Николаевич Нарожный
Keyword(s):  
Dark Matter ◽  
Electromagnetic Radiation ◽  
Microwave Radiation ◽  
Relaxation Processes ◽  
Main Question ◽  
Conservation Of Energy ◽  
The Earth ◽  
Starting Point ◽  
The Universe ◽  
Cosmic Microwave Radiation

The question of the possible origin of one of the components of dark matter filling the galaxies is considered. The analysis of the “fate” of stellar electromagnetic radiation under the conditions of the eternal Universe is taken as a starting point. Based on a comparison of the average lifetime of a star in the active phase and the lifetime of the non-absorbed part of its radiation, it is concluded that the Universe is filled with stellar electromagnetic radiation. However, based on existing concepts, as well as the red shift found in the spectra of distant galaxies, the addition of new radiation to the existing in the Universe will be accompanied by the “disappearance” of radiation in the most long-wave region, that is, there will be a violation of the law of conservation of energy. The main question arises: can radiation as well as energy disappear without a trace? The answer is negative, and it is explained by the involvement of the mechanism of dissipative losses during the radiative transfer by the expanses of the Universe. For this purpose, an assumption is introduced about the presence of an agent's medium interacting with quanta of radiation with the help of excessively weak forces. It is hypothesized that photons that fall into the low-frequency region (microwave band and ranges close to it) are able to pair up in an agent's medium, creating neutral particles of extremely small masses (about 0.0013 eV). These particles - bosons - are particles of the agent itself. Based on the nature of the agent, some observational data related to the Solar System (increased distance between the Sun and the Earth, the "floating" value of the G gravitation constant, scintillations of cosmic microwave radiation), as well as detected deviations observed during spacecraft acceleration with gravitational slingshots near the Earth (Galileo, NEAR, Rosetta, Messenger, Cassini). In addition, this hypothesis regarding the origin and properties of the agent explains some of the results of laboratory research: scintillations of the rates of chemical and biochemical reactions, floating "zero" of high-precision instruments and, possibly, relaxation processes in elastic solids (material aging). The main conclusions: cosmic microwave radiation is a remnant of stellar radiation, and the agent's medium is a component of dark matter, which is closely associated with cosmic microwave radiation. Other dark matter components are extinct stars, their various cold fragments, including gases and dust, and possibly other deeper structural levels of matter.

scholarly journals A MODEL OF A SIMPLE, BARYON-DOMINATED UNIVERSE THAT EXPANDS AT AN EVER-INCREASING RATE WITHOUT RELYING ON VACUUM ENERGY (Λ)

2011 ◽  
Vol 26 (33) ◽  
pp. 2501-2521
Author(s):  
GREG P. PROPER
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Dark Energy ◽  
Vacuum Energy ◽  
Absolute Magnitude ◽  
Short Paper ◽  
Modern Cosmology ◽  
Spacetime Metric ◽  
The Universe ◽  
Prevailing View

The prevailing view in modern cosmology is that the universe is comprised of immense quantities of exotic materials (i.e. Dark Matter and Dark Energy) that have yet to be positively identified. However, there is also a small group of scientists who believe that the answer to this dilemma is to be found in the modification of gravity (i.e. General Relativity). This short paper states that if we make the bold assumption that all objects/observers are comprised of sets of spacetime coordinates that change (albeit slowly) as the universe ages, then three puzzles that currently confront cosmologists, astronomers and astrophysicists can easily be answered using relatively simple calculations. The condition necessary to explore this possibility can be obtained if one postulates that relativistic gravitational potential lessens (in absolute magnitude) everywhere as the universe ages (n). That is, the spacetime metric gμν(x)→gμν(x, n). If gravity behaves in this manner, then it can be shown that it is the causitive agent of indeterminism in nature.

scholarly journals Determination of “inos” Masses Composing Galactic Halos

1987 ◽  
Vol 124 ◽  
pp. 723-726
Author(s):  
D. J. Song ◽  
R. Ruffini
Keyword(s):  
Dark Matter ◽  
Physical Properties ◽  
Galactic Halos ◽  
Modern Cosmology ◽  
The Universe

One of the most important discoveries in modern cosmology and astrophysics is that the dark matter dominates at every scale of the Universe (Rubin et al., 1978, Forman et al., 1985, Faber and Gallagher, 1979, Sancisi, 1987). The problem that follows is to understand the components of the dark matter and to determine the physical properties of these components.

Matter: A Very Short Introduction

2019 ◽  
Author(s):  
Geoff Cottrell
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Big Bang ◽  
Short Introduction ◽  
Quantum Properties ◽  
Quantum Matter ◽  
Normal Matter ◽  
Fundamental Forces ◽  
The Big Bang ◽  
The Universe

Matter: A Very Short Introduction explains matter—the stuff of which your body and the universe is made—from elementary particles, to atoms, humans, planets, up to the superclusters of galaxies. Familiar solids, liquids, and gases are described, as well as plasmas, exotic forms of quantum matter, and antimatter. This VSI outlines the quantum properties of atoms, the fundamental forces of nature, and how the different forms of matter arise. The origins of matter are traced to the Big Bang, 13.8 billion years ago. However, all the familiar normal matter constitutes only 5% of the matter that exists. The remainder comes in two mysterious forms: dark matter and dark energy, which are discussed.

DENSITY PERTURBATIONS AND THE CHAPLYGIN GAS

2009 ◽  
Vol 24 (08n09) ◽  
pp. 1674-1677
Author(s):  
SANDRO SILVA E COSTA
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Power Spectrum ◽  
Cosmological Model ◽  
Chaplygin Gas ◽  
Scale Factor ◽  
Modified Chaplygin Gas ◽  
Modern Cosmology ◽  
Density Perturbations ◽  
The Universe

One approach in modern cosmology consists in supposing that dark matter and dark energy are different manifestations of a single 'quartessential' fluid. Following such idea, this work presents a summary of some studies of the evolution of density perturbations in a flat cosmological model with a modified Chaplygin gas acting as a single component. Our goal is to obtain properties of the model which can be used to distinguish it from another cosmological models which have the same solutions for the general evolution of the scale factor of the universe, even without the construction of the power spectrum. Both our analytical and numerical results clearly indicate as one interesting feature of the model the presence of peaks in the evolution of the density constrast.

scholarly journals A multi-messenger view of cosmic dawn: Conquering the final frontier

2021 ◽  
Vol 30 (14) ◽  
Author(s):  
Hamsa Padmanabhan
Keyword(s):  
Dark Matter ◽  
Large Scale ◽  
Current Knowledge ◽  
Cosmological Parameters ◽  
Observational Cosmology ◽  
First Stars ◽  
Cosmological Principle ◽  
Normal Matter ◽  
The Universe ◽  
Einstein’S General Relativity

The epoch of Cosmic Dawn, when the first stars and galaxies were born, is widely considered as the final frontier of observational cosmology today. Mapping the period between Cosmic Dawn and the present-day provides access to more than 90% of the baryonic (normal) matter in the universe, and unlocks several thousand times more Fourier modes of information than available in today’s cosmological surveys. We review the progress in modeling baryonic gas observations as tracers of the cosmological large-scale structure from Cosmic Dawn to the present day. We illustrate how the description of dark matter haloes can be extended to describe baryonic gas abundances and clustering. This innovative approach allows us to fully utilize our current knowledge of astrophysics to constrain cosmological parameters from future observations. Combined with the information content of multi-messenger probes, this will also elucidate the properties of the first supermassive black holes at Cosmic Dawn. We present a host of fascinating implications for constraining physics beyond the [Formula: see text]CDM model, including tests of the theories of inflation and the cosmological principle, the effects of nonstandard dark matter, and possible deviations from Einstein’s general relativity on the largest scales.

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