scholarly journals OBTAINING NEUTRON MATTER AND HYPERHEAVY NUCLEI: POSSIBLE QUANTUM-TECHNOLOGICAL INSTRUMENTAL APPROACHES

2021 ◽  
Vol 34 ◽  
pp. 23-29
Author(s):  
G.B. Ryazantsev ◽  
V.I. Vysotskii ◽  
G.K. Lavrenchenko ◽  
S.S. Nedovesov

Possible mechanisms of creation of both hyperheavy nuclei by electron-nuclear collapse and              neutron matter by condensation of ultracold neutrons are discussed. The fundamental possibility of the existence of  such objects was previously substantiated by A.B.Migdal, who suggested that the known set of proton-neutron nuclei with mass numbers from 0 to 300 and a maximum specific binding energy of about 8 MeV / nucleon at A≈60 corresponds to the first region, beyond which (starting from about the charge Z≈ ( hc/e2 )3/2 ≈1600 ) there is an additional region describing a possible state of nuclear matter, stabilized by a pion condensate. In this region, the maximum specific energy corresponds to ≈15 MeV / nucleon at A ≈ 100000. It is shown that neutron matter can be obtained under certain conditions, and its systematization can be realized as an addition to the Periodic Table. When solving such problems, it becomes quite real to study not only physical, but also chemical, and possibly engineering and technical properties. Analysis shows that the stability of neutron matter at the microlevel is ensured by the Tamm interaction and the Hund beta equilibrium. Such matter can be quite stable    not only on the mega-level (neutron stars) due to gravitational interaction, as was a priori assumed earlier, but also on the scale of "ordinary" matter. The process of neutronization is possible not only with critical gravitational interaction, but also by other mechanisms (supercritical increase in the atomic number of elements due to electron-nuclear collapse and condensation of ultracold neutrons), which opens the way to the fundamental possibility of obtaining both neutron matter in laboratory conditions and superheavy nuclei. Based on the works of Migdal, Tamm and Hund, the possibility of the existence of stable neutron matter (with Z >> 175, N >> Z, A> 10 3 -10 5 and a size of 200-300 femtometers and more) is argued at the microlevel, and not only at the mega-level, as is now considered in astrophysics. A critical analysis of the well-established concept of the minimum possible mass of neutron stars is carried out. The following quantum technological approaches to the realization of UCN condensation are proposed: 1. Slow isothermal compression; 2. Refrigerator for dissolving helium-3 and helium-4; 3. Use of a conical concentrator for UCN focusing (Vysotskii cone); 4. Magnetic trap; 5. Additional UCN laser cooling. Neutron matter is considered as a potential cosmological candidate for dark matter. One should take into account the possibility of the formation of fragments of neutron matter as dark matter (neutral, femto-, pico- and nanoscale, the cooling of relics makes it difficult to detect them by now) already at the initial origin of the Universe, which is the dominant process. The observable part of the Universe is formed by the residual part of protons, and then by decayed single neutrons and unstable fragments of neutron matter (with Z> 175, N >> Z, but A <10 3 -10 5 ).

2020 ◽  
Vol 29 (14) ◽  
pp. 2043028
Author(s):  
M. Ángeles Pérez-García ◽  
Joseph Silk

Neutron Stars (NSs) are compact stellar objects that are stable solutions in General Relativity. Their internal structure is usually described using an equation of state that involves the presence of ordinary matter and its interactions. However there is now a large consensus that an elusive sector of matter in the universe, described as dark matter, remains as yet undiscovered. In such a case, NSs should contain both, baryonic and dark matter. We argue that depending on the nature of the dark matter and in certain circumstances, the two matter components would form a mixture inside NSs that could trigger further changes, some of them observable. The very existence of NSs constrains the nature and interactions of dark matter in the universe.


Author(s):  
Arun Kenath ◽  
Kiren O. V. ◽  
Sivaram C

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.


Author(s):  
Timothy Clifton

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.


2018 ◽  
Vol 33 (31) ◽  
pp. 1844020 ◽  
Author(s):  
T. F. Motta ◽  
P. A. M. Guichon ◽  
A. W. Thomas

Recent proposals have suggested that a previously unknown decay mode of the neutron into a dark matter particle could solve the long lasting measurement problem of the neutron decay width. We show that, if the dark particle in neutron decay is the major component of the dark matter in the universe, this proposal is in disagreement with modern astrophysical data concerning neutron star masses.


2020 ◽  
Vol 29 (14) ◽  
pp. 2043017
Author(s):  
Jenny Wagner

In our current best cosmological model, the vast majority of matter in the universe is dark, consisting of yet undetected, nonbaryonic particles that do not interact electro-magnetically. So far, the only significant evidence for dark matter has been found in its gravitational interaction, as observed in galaxy rotation curves or gravitational lensing effects. The inferred dark matter agglomerations follow almost universal mass density profiles that can be reproduced well in simulations, but have eluded an explanation from a theoretical viewpoint. Forgoing standard (astro-)physical methods, I show that it is possible to derive these profiles from an intriguingly simple mathematical approach that directly determines the most likely spatial configuration of a self-gravitating ensemble of collisionless dark matter particles.


Author(s):  
А. Н. Нарожный

A possible component of dark matter is considered. Astronomer began to talk about this matter for a long time, when the speed of movement of galaxies in the clusters was coordinated with classical mechanics. Subsequently, the idea of dark matter became used in the dynamics of stars and lineling phenomena. The observational data of astronomy and astrophysics indicate another path, which leads to the idea of the existence of dark matter, if these data are considered through the prism of the main principles and laws of natural science. On this path, the component of dark matter (DM) appears as an environment in the universe necessary to ensure the life of galaxies. The origin of the dark matter and the functions performed by it are binding to star electromagnetic radiation (SER). Features of the interaction of a two-component system - DM and SER - the basis of all further conclusions. First of all, the outer space is considered filled with subtle forms of matter. It is assumed that DM belongs to them. The presence of two giant material objects distributed over the entire space of the Universe, DM and SER - means their interaction among themselves. First, it follows from dialectic, arguing about the relationship of phenomena in nature. Secondly, from the interpretation of the results of measurements of cosmic microwave radiation obtained by the Arcade system (NASA, 2006). A two-component environment - DM and SER - contains all the baryon matter of the universe, ranging from elementary particles and ending with galactic clusters. Support for "life" of baryon matter is carried out through a number of functions performed by this medium. It is assumed that the star radiation, spreading the space, gives its energy to the dark component. The photons shifted into the microwave region are capable of pairing unaging among themselves in counter courses and small sighting distances. Appearing bosons particles correlate with dark matter. These particles have zero spin or two. Their spectrum of mass turns out to be continuous, the maximum mass of the particle is given. The assumption of energy transmission by a quantum dissemination environment and the microwave hypothesis is consistently explained by many observation results. First of all, it is a red shift in galaxies spectra and the presence of a large cosmic microwave background with its intensity variations at relatively small time intervals. DM particles due to the gravitational interaction return the energy back to its baryonic sources. At the same time, the dark component additionally fills the central supermassive object of the galaxy, which in the quasar phase conducts utilization of star waste with hydrogen regeneration. It is DM that provides large energies allocated by quasars. Given the small part of the star matter, turning into the SER, it is shown that the particles of DM are a medium with a relatively low temperature. It is concluded that DM and SER are a comprehensive dynamic environment in which the baryon matter of the universe lives and develops. Through this two-component "ocean" of matter, all major metabolic processes supporting the "life" of galaxies are carried out.


2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Alexandre Deur

Abstract Analyses of internal galaxy and cluster dynamics typically employ Newton’s law of gravity, which neglects the field self-interaction effects of General Relativity. This may be why dark matter seems necessary. The universe evolution, on the other hand, is treated with the full theory, General Relativity. However, the approximations of isotropy and homogeneity, normally used to derive and solve the universe evolution equations, effectively suppress General Relativity’s field self-interaction effects and this may introduce the need for dark energy. Calculations have shown that field self-interaction increases the binding of matter inside massive systems, which may account for galaxy and cluster dynamics without invoking dark matter. In turn, energy conservation dictates that the increased binding must be balanced by an effectively decreased gravitational interaction outside the massive system. In this article, such suppression is estimated and its consequence for the Universe’s evolution is discussed. Observations are reproduced without need for dark energy.


Universe ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 101
Author(s):  
Maxim Eingorn ◽  
Andrew McLaughlin ◽  
Ezgi Canay ◽  
Maksym Brilenkov ◽  
Alexander Zhuk

We investigate the influence of the chimney topology T×T×R of the Universe on the gravitational potential and force that are generated by point-like massive bodies. We obtain three distinct expressions for the solutions. One follows from Fourier expansion of delta functions into series using periodicity in two toroidal dimensions. The second one is the summation of solutions of the Helmholtz equation, for a source mass and its infinitely many images, which are in the form of Yukawa potentials. The third alternative solution for the potential is formulated via the Ewald sums method applied to Yukawa-type potentials. We show that, for the present Universe, the formulas involving plain summation of Yukawa potentials are preferable for computational purposes, as they require a smaller number of terms in the series to reach adequate precision.


2021 ◽  
Vol 32 ◽  
pp. 100796
Author(s):  
Raul Ciancarella ◽  
Francesco Pannarale ◽  
Andrea Addazi ◽  
Antonino Marcianò
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