scholarly journals Stability and pulsation of the first dark stars

2021 ◽  
Vol 503 (3) ◽  
pp. 3677-3691
Author(s):  
Tanja Rindler-Daller ◽  
Katherine Freese ◽  
Richard H D Townsend ◽  
Luca Visinelli
Keyword(s):  
Energy Source ◽  
Dark Matter ◽  
Mass Loss ◽  
Stellar Evolution ◽  
Weakly Interacting Massive Particles ◽  
Acoustic Modes ◽  
Accretion Rates ◽  
Dynamical Instabilities ◽  
First Time ◽  
The Universe

ABSTRACT The first bright objects to form in the Universe might not have been ‘ordinary’ fusion-powered stars, but ‘dark stars’ (DSs) powered by the annihilation of dark matter (DM) in the form of weakly interacting massive particles (WIMPs). If discovered, DSs can provide a unique laboratory to test DM models. DSs are born with a mass of the order of M⊙ and may grow to a few million solar masses; in this work we investigate the properties of early DSs with masses up to $\sim \! 1000 \, \mathrm{ M}_\odot$, fueled by WIMPS weighing 100 GeV. We improve the previous implementation of the DM energy source into the stellar evolution code mesa. We show that the growth of DSs is not limited by astrophysical effects: DSs up to $\sim \!1000 \, \mathrm{ M}_{\odot }$ exhibit no dynamical instabilities; DSs are not subject to mass-loss driven by super-Eddington winds. We test the assumption of previous work that the injected energy per WIMP annihilation is constant throughout the star; relaxing this assumption does not change the properties of the DSs. Furthermore, we study DS pulsations, for the first time investigating non-adiabatic pulsation modes, using the linear pulsation code gyre. We find that acoustic modes in DSs of masses smaller than $\sim \! 200 \, \mathrm{ M}_\odot$ are excited by the κ − γ and γ mechanism in layers where hydrogen or helium is (partially) ionized. Moreover, we show that the mass-loss rates potentially induced by pulsations are negligible compared to the accretion rates.

scholarly journals Dark Stars: Dark matter in the first stars leads to a new phase of stellar evolution

2008 ◽  
Vol 4 (S255) ◽  
pp. 56-60 ◽  
Author(s):  
Katherine Freese ◽  
Douglas Spolyar ◽  
Anthony Aguirre ◽  
Peter Bodenheimer ◽  
Paolo Gondolo ◽  
...  
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Cross Section ◽  
Stellar Evolution ◽  
Weakly Interacting Massive Particles ◽  
First Stars ◽  
History Of ◽  
Born Again ◽  
The Universe ◽  
New Phase

AbstractThe first phase of stellar evolution in the history of the universe may be Dark Stars, powered by dark matter heating rather than by fusion. Weakly interacting massive particles, which are their own antiparticles, can annihilate and provide an important heat source for the first stars in the the universe. This talk presents the story of these Dark Stars. We make predictions that the first stars are very massive (~800M⊙), cool (6000 K), bright (~106L⊙), long-lived (~106years), and probable precursors to (otherwise unexplained) supermassive black holes. Later, once the initial DM fuel runs out and fusion sets in, DM annihilation can predominate again if the scattering cross section is strong enough, so that a Dark Star is born again.

scholarly journals DO RECENT SUPERNOVAE Ia OBSERVATIONS TEND TO RULE OUT ALL THE COSMOLOGIES?

2007 ◽  
Vol 16 (10) ◽  
pp. 1641-1651 ◽  
Author(s):  
RAM GOPAL VISHWAKARMA
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Gravitational Lensing ◽  
Weakly Interacting Massive Particles ◽  
Cosmological Models ◽  
Accelerated Expansion ◽  
Standard Candle ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Rule Out

Dark energy and the accelerated expansion of the universe have been the direct predictions of the distant supernovae Ia observations which are also supported, indirectly, by the observations of the CMB anisotropies, gravitational lensing and the studies of galaxy clusters. Today these results are accommodated in what has become the concordance cosmology: a universe with flat spatial sections t = constant with about 70% of its energy in the form of Einstein's cosmological constant Λ and about 25% in the form of dark matter (made of perhaps weakly-interacting massive particles). Though the composition is weird, the theory has shown remarkable successes at many fronts. However, we find that as more and more supernovae Ia are observed, more accurately and towards higher redshift, the probability that the data are well-explained by the cosmological models decreases alarmingly, finally ruling out the concordance model at more than 95% confidence level. This raises doubts against the "standard candle"-hypothesis of the supernovae Ia and their use in constraining the cosmological models. We need a better understanding of the entire SN Ia phenomenon in order to extract cosmological consequences from them.

scholarly journals DARK MATTER DETECTION IN THE LIGHT OF RECENT EXPERIMENTAL RESULTS

2004 ◽  
Vol 19 (19) ◽  
pp. 3093-3169 ◽  
Author(s):  
CARLOS MUÑOZ
Keyword(s):  
Dark Matter ◽  
Direct Detection ◽  
Theoretical Models ◽  
Weakly Interacting Massive Particles ◽  
The Standard Model ◽  
The World ◽  
Nuclear Recoils ◽  
M Theory ◽  
The Universe ◽  
Matter Detection

The existence of dark matter was suggested, using simple gravitational arguments, seventy years ago. Although we are now convinced that most of the mass in the Universe is indeed some nonluminous matter, we still do not know its composition. The problem of the dark matter in the Universe is reviewed here. Particle candidates for dark matter are discussed with particular emphasis on Weakly Interacting Massive Particles (WIMP's). Experiments searching for these relic particles, carried out by many groups around the world, are also reviewed, paying special attention to their direct detection by observing the elastic scattering on target nuclei through nuclear recoils. Finally, we concentrate on the theoretical models predicting WIMP's, and in particular on supersymmetric extensions of the standard model, where the leading candidate for WIMP, the neutralino, is present. There, we compute the cross-section for the direct detection of neutralinos, and compare it with the sensitivity of detectors. We mainly discuss supergravity, superstring and M theory scenarios.

TOWARDS DETECTION OF LOW MASS WIMPs (MWIMP<10GeV/c2): MINI-REVIEW

2013 ◽  
Vol 28 (26) ◽  
pp. 1330033 ◽  
Author(s):  
A. K. DRUKIER ◽  
S. NUSSINOV
Keyword(s):  
Dark Matter ◽  
Weakly Interacting Massive Particles ◽  
Dark Matter Candidate ◽  
Weakly Interacting ◽  
Reliable Detection ◽  
Massive Particles ◽  
Low Mass ◽  
Nuclear Targets ◽  
The Universe

Weakly Interacting Massive Particles (WIMPs) may constitute most of the matter in the Universe. There are intriguing results from DAMA/LIBRA, CoGeNT and CRESST-II, and more recently CDMS-Si suggesting a relatively light dark matter candidate of mass <10 GeV /c2. At the same time, experiments using heavy nuclear targets such as CDMS-Ge and XENON detectors suggest that there is no DM candidates with MW>15 GeV /c2. We review the existing experiments and the problems associated with light mass WIMP detection. We find that all six experiments considered (DAMA, CoGeNT, CRESST, CDMS-Si, CDMS-Ge, XENON) are consistent if one assumes that the mass of WIMP is lower than expected: 3.4<MW<6.8 GeV /c2. This is followed by a discussion of the properties of "new" detectors, which may enable more reliable detection of low mass WIMPs.

scholarly journals Thermal production of sexaquarks in heavy-ion collisions

2021 ◽  
Vol 36 (25) ◽  
Author(s):  
David Blaschke ◽  
Larissa Bravina ◽  
Kyrill Bugaev ◽  
Glennys R. Farrar ◽  
Boris Grinyuk ◽  
...  
Keyword(s):  
Dark Matter ◽  
Heavy Ion Collisions ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Dark Matter Candidate ◽  
Ion Collisions ◽  
Great Relevance ◽  
Age Of The Universe ◽  
First Time ◽  
The Universe

We present new results on the thermal production yield of a hypothetical state made of six quarks [Formula: see text] assuming its production in heavy-ion collisions at the CERN Large Hadron Collider (LHC). A state with this quark content and mass low enough to be stable against decay in timescales of the order of the age of the Universe has been hypothesized by one of us (G. Farrar) and has been discussed as a possible dark matter candidate. In this work, we address for the first time the thermal production rate that can be expected for this state in heavy-ion collisions at colliders. For this estimate we use a thermal model which has been shown to describe accurately the production of hadrons and nuclei in heavy-ion collisions at LHC energy. This estimate is of great relevance for sexaquark searches at colliders as well as for its consideration as a dark matter candidate and for the composition of neutron stars.

scholarly journals In the Quest for Cosmic Rotation

Universe ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 14 ◽  
Author(s):  
Vladimir A. Korotky ◽  
Eduard Masár ◽  
Yuri N. Obukhov
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Dark Energy ◽  
Angular Velocity ◽  
Natural Explanation ◽  
Acceleration Parameter ◽  
Electronic Catalogs ◽  
Celestial Sphere ◽  
First Time ◽  
The Universe

This paper analyzes the problem of global rotation in general relativity (GR) theory. Simple cosmological models with rotation and expansion are presented, which give a natural explanation of the modern values of the acceleration parameter at different red shifts without involving the concepts of “dark energy” and “dark matter”. It is shown that due to the smallness of the cosmological rotation, for its detection one should use observations that do not depend on the magnitude of the angular velocity of the Universe. Such tests include the effects of the cosmic mirror and the cosmic lens. For the first time on the basis of modern electronic catalogs the search on the celestial sphere of images of our Galaxy and other galaxies is made. Viable candidates for both effects have been found.

scholarly journals Effects of dark matter annihilation on the first stars

2008 ◽  
Vol 4 (S255) ◽  
pp. 61-65 ◽  
Author(s):  
F. Iocco ◽  
A. Bressan ◽  
E. Ripamonti ◽  
R. Schneider ◽  
A. Ferrara ◽  
...  
Keyword(s):  
Energy Source ◽  
Dark Matter ◽  
Main Sequence ◽  
Equilibrium Phase ◽  
Stellar Structure ◽  
Dark Matter Halo ◽  
Dark Matter Annihilation ◽  
Helium Burning ◽  
First Stars ◽  
The Universe

AbstractWe study the evolution of the first stars in the universe (Population III) from the early pre–Main Sequence (MS) until the end of helium burning in the presence of WIMP dark matter annihilation inside the stellar structure. The two different mechanisms that can provide this energy source are the contemporary contraction of baryons and dark matter, and the capture of WIMPs by scattering off the gas with subsequent accumulation inside the star. We find that the first mechanism can generate an equilibrium phase, previously known as a dark star, which is transient and present in the very early stages of pre–MS evolution. The mechanism of scattering and capture acts later, and can support the star virtually forever, depending on environmental characteristics of the dark matter halo and on the specific WIMP model.

Dark Coulomb binding of heavy neutrinos of fourth family

2015 ◽  
Vol 24 (13) ◽  
pp. 1545008 ◽  
Author(s):  
K. M. Belotsky ◽  
E. A. Esipova ◽  
M. Yu. Khlopov ◽  
M. N. Laletin
Keyword(s):  
Dark Matter ◽  
Weakly Interacting Massive Particles ◽  
Fourth Generation ◽  
Upper Limits ◽  
Charged Clusters ◽  
Primordial Abundance ◽  
Text Interaction ◽  
The Universe ◽  
Dominant Part ◽  
Direct Dark Matter

Direct dark matter searches put severe constraints on the weakly interacting massive particles (WIMPs). These constraints cause serious troubles for the model of stable neutrino of fourth generation with mass around 50[Formula: see text]GeV. Though the calculations of primordial abundance of these particles make them in the charge symmetric case a sparse subdominant component of the modern dark matter, their presence in the universe would exceed the current upper limits by several orders of the magnitude. However, if quarks and leptons of fourth generation possess their own Coulomb-like [Formula: see text]-interaction, recombination of pairs of heavy neutrinos and antineutrinos and their annihilation in the “neutrinium” atoms can play important role in their cosmological evolution, reducing their modern abundance far below the experimental upper limits. The model of stable fourth generation assumes that the dominant part of dark matter is explained by excessive [Formula: see text] antiquarks, forming [Formula: see text] charged clusters, bound with primordial helium in nuclear-interacting O-helium (OHe) dark atoms. The [Formula: see text] charge conservation implies generation of the same excess of fourth generation neutrinos, potentially dangerous WIMP component of this scenario. We show that due to [Formula: see text]-interaction recombination of fourth neutrinos with OHe hides these WIMPs from direct WIMP searches, leaving the negligible fraction of free neutrinos, what makes their existence compatible with the experimental constraints.

scholarly journals Quantum Theory of Gravity and Arthur Eddingtons Fundamental Theory

2021 ◽  
Vol 2 (11) ◽  
pp. 1092-1100
Author(s):  
Konstantinov SI
Keyword(s):  
Dark Matter ◽  
Quantum Theory ◽  
Quantum Gravity ◽  
Dark Matter Halo ◽  
Fundamental Theory ◽  
Theories Of Gravity ◽  
Theory Of Gravity ◽  
First Time ◽  
Contraction And Expansion ◽  
The Universe

For the first time, the article presents the Quantum Theory of Gravity, covering not only the microcosm of elementary particles, but also the macrocosm of planets, stars and black holes. This relational approach to gravity was consistently presented in Arthur Eddington's monograph “Fundamental Theory”. In the theory of quantum gravity proposes to consider instead of gravity holes in the curved space-time of Einstein's general relativity, gravitational funnels formed by the rotation of planets, stars and galaxies in a dark matter halo. The change in the gravitational potential in the funnels occurs instantly in all areas of the gravitational funnel space in accordance with the pressure gradient described by the Euler-Bernoulli equation for superfluid continuous media. The new cosmological theory represents the evolution of the universe and dark holes without a singularity. The disordered alternation of the processes of contraction and expansion of individual regions of the infinite Universe realizes the circulation of baryonic and dark matter, which allows it to exist indefinitely, bypassing the state of equilibrium. Numerical modeling allows us to assert that the theory of quantum gravity is the most reliable of the three generally accepted theories of gravity.

scholarly journals Strong constraints from COSINE-100 on the DAMA dark matter results using the same sodium iodide target

2021 ◽  
Author(s):  
Govinda Adhikari ◽  
E. Barbosa de Souza ◽  
N. Carlin ◽  
J.J. Choi ◽  
S. Choi ◽  
...  
Keyword(s):  
Dark Matter ◽  
Sodium Iodide ◽  
Weakly Interacting Massive Particles ◽  
Dark Matter Halo ◽  
Annual Modulation ◽  
Interaction Hypothesis ◽  
Order Of Magnitude ◽  
Modulation Signal ◽  
Alternative Scenarios ◽  
First Time

Abstract It is a long-standing debate as to whether or not the annual modulation in the event rate observed by the DAMA sodium iodide experiment is caused by the interaction of dark matter particles. To resolve this issue, several groups have been working to develop new experiments with the aim of reproducing or refuting DAMA's results using the same sodium iodide target medium. The COSINE-100 experiment is one of these that is currently operating with 106 kg of low-background sodium iodide crystals at the Yangyang underground laboratory. Analysis of the initial 59.5 days of COSINE-100 data showed that the annual modulation signal reported by DAMA is inconsistent with explanation using spin-independent interaction of weakly interacting massive particles (WIMPs), a favored candidate of dark matter particles, with sodium or iodine nuclei in the context of the standard halo mode. However, this first result left open interpretations using certain alternative dark matter models, dark matter halo distributions, and detector responses that could allow room for consistency between DAMA and COSINE-100. Here we present new results from over 1.7 years of COSINE-100 operation with improved event selection and energy threshold reduced from 2 keV to 1 keV. We find an order of magnitude improvement in sensitivity, sufficient for the first time to strongly constrain these alternative scenarios, as well as to further strengthen the previously observed inconsistency with the WIMP-nucleon spin-independent interaction hypothesis.

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