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Sep 25, 2021
09/21
by
(Hall, Perez
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To commemorate the 70th birthday of the world leader, the great scientist, philosophy thinker, sociologist, physicist and cosmologist Fang Ruida (Hall, Perez) 2019v.3.1 (Perez) Commemorate the 70th birthday of the world leader, great scientist, philosopher, thinker, sociologist, physicist, cosmologist Fang Ruida (1949.5.14--2019.5.14) Perez-Hall 2019v. 3.1 ——------------------------------------------------ ----------------- Selections from Fangruida's Speech: The Significance of...
Topic: biography cosmology world
4
4.0
Jun 29, 2018
06/18
by
A P Balachandran; Babar Qureshi
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In QED and QCD [1, 2], infrared photons and gluons alter the Hilbert space of the theory so that the in and out states live in a Hilbert space carrying a representation of basic commutation relations which is non-equivalent to the standard Fock representation, leading to spontaneous breakdown of Lorentz symmetry and physical effects. These results are generalized here to quantum gravity regarded as an SL(2; C) gauge theory and the shift of the ADM energy density and mass from infrared spin...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1601.07370
4
4.0
Jun 30, 2018
06/18
by
A. A. Abdo; A. U. Abeysekara; B. T. Allen; T. Aune; A. S. Barber; D. Berley; J. Braun; C. Chen; G. E. Christopher; R. S. Delay; T. DeYoung; B. L. Dingus; R. W. Ellsworth; N. Fraija; M. M. González; J. A. Goodman; E. Hays; C. M. Hoffman; P. H. Hüntemeyer; A. Imran; B. E. Kolterman; J. T. Linnemann; A. Marinelli; J. E. McEnery; T. Morgan; A. I. Mincer; P. Nemethy; B. Patricelli; J. Pretz; J. M. Ryan; P. M. Saz Parkinson; M. Schneider; A. Shoup; G. Sinnis; A. J. Smith; V. Vasileiou; G. P....
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TeV flaring activity with time scales as short as tens of minutes and an orphan TeV flare have been observed from the blazar Markarian 421 (Mrk 421). The TeV emission from Mrk 421 is believed to be produced by leptonic synchrotron self-Compton (SSC) emission. In this scenario, correlations between the X-ray and the TeV fluxes are expected, TeV orphan flares are hardly explained and the activity (measured as duty cycle) of the source at TeV energies is expected to be equal or less than that...
Topics: High Energy Astrophysical Phenomena, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1401.2161
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14
Jun 27, 2018
06/18
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A. A. Abdujabbarov; L. Rezzolla; B. J. Ahmedov
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eye 14
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A large international effort is under way to assess the presence of a shadow in the radio emission from the compact source at the centre of our Galaxy, Sagittarius A$^*$ (Sgr A$^*$). If detected, this shadow would provide the first direct evidence of the existence of black holes and that Sgr A$^*$ is a supermassive black hole. In addition, the shape of the shadow could be used to learn about extreme gravity near the event horizon and to determine which theory of gravity better describes the...
Topics: Solar and Stellar Astrophysics, General Relativity and Quantum Cosmology, High Energy Astrophysical...
Source: http://arxiv.org/abs/1503.09054
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8.0
Jun 26, 2018
06/18
by
A. A. Asgari; A. H. Abbassi
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eye 8
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During the inflationary epoch,geometry of the universe may be described by quasi-de Sitter space. On the other hand,maximally extended de Sitter metric in the comoving coordinates accords with a special FLRW model with positive spatial curvature,so in this article we focus on the positively curved inflationary paradigm.For this purpose,first we derive the power spectra of comoving curvature perturbation and primordial gravitational waves in a positively curved FLRW universe according to the...
Topics: General Relativity and Quantum Cosmology, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.07089
5
5.0
Jun 30, 2018
06/18
by
A. A. Coley; D. D. McNutt
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eye 5
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In this paper we study the stationary horizons of the rotating black ring and the supersymmetric black ring spacetimes in five dimensions. In the case of the rotating black ring we use Weyl aligned null directions to algebraically classify the Weyl tensor, and utilize an adapted Cartan algorithm in order to produce Cartan invariants. For the supersymmetric black ring we employ the discriminant approach and repeat the adapted Cartan algorithm. For both of these metrics we are able to construct...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1704.03055
4
4.0
Jun 30, 2018
06/18
by
A. A. Garcia Diaz; G. Gutierrez Cano
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In this report a detailed derivation of the dynamical equations for an n dimensional heterotic string theory of the Horowitz type is carried out in the string frame and in the Einstein frame too. In particular, the dynamical equations of the three dimensional string theory are explicitly given. The relation of the Horowitz Welch and Horne Horowitz string black hole solution is exhibited. The Chan Mann charged dilaton solution is derived and the subclass of string solutions field is explicitly...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1412.5618
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6.0
Jun 30, 2018
06/18
by
A. A. Garcia-Diaz; G. Gutierrez Cano
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eye 6
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Using the Schwarzschild coordinate frame for a static cyclic symmetric metric in 2 + 1 Einstein gravity coupled to a electric Maxwell field and a dilaton logarithmically depending on the radial coordinate in the presence of an exponential potential the general solution of the Einstein Maxwell dilaton equations is derived and it is identified with the Chan Mann charged dilaton solution. Via a general SL(2;R) transformation, applied on the obtained charged dilaton metric, a family of stationary...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1412.5621
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19
Jun 30, 2018
06/18
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A. A. Grib
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Current thinking on the interpretation of quantum physics is reviewed, with special detail given to the Copenhagen and Everett many-worlds interpretations.
Topics: Quantum Physics, Physics, General Relativity and Quantum Cosmology, History and Philosophy of...
Source: http://arxiv.org/abs/1404.2784
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4.0
Jun 30, 2018
06/18
by
A. A. Grib; Yu. V. Pavlov
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eye 4
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It is shown that the energy in the centre of mass frame of two colliding particles in free fall at any point of the ergosphere of the rotating black hole can grow without limit for fixed energy values of particles on infinity. The effect takes place for large negative values of the angular momentum of one of the particles. It occurs that the geodesics with negative energy in equatorial plane of rotating black holes cannot originate or terminate inside the ergosphere. Their length is always...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1401.0368
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5.0
Jun 29, 2018
06/18
by
A. A. Grib; Yu. V. Pavlov
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eye 5
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Results on particle creation from vacuum by the gravitational field of the expanding Friedmann Universe are presented. Finite results for the density of particles and the energy density for created particles are given for different exact solutions for different regimes of the expansion of the Universe. The results are obtained as for conformal as for nonconformal particles. The hypothesis of the origination of visible matter from the decay of created from vacuum superheavy particles identified...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1601.06618
4
4.0
Jun 30, 2018
06/18
by
A. A. Grib; Yu. V. Pavlov
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eye 4
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Geodesic completeness needs existence near the horizon of the black hole of "white hole" geodesics coming from the region inside of the horizon. Here we give the classification of all such geodesics with the energies $E/m \le 1$ for the Schwarzschild and Kerr's black hole. The collisions of particles moving along the "white hole" geodesics with those moving along "black hole" geodesics are considered. Formulas for the increase of the energy of collision in the...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1410.5736
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20
Jun 27, 2018
06/18
by
A. A. Grib; Yu. V. Pavlov
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eye 20
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The aim of the paper is the consideration of particle collisions in the vicinity of the horizon of rotating black holes. Existence of geodesics for massive and massless particles arising from the region inside of the gravitational radius in ergosphere leads to the different possibilities to get very high energy in the centre mass frame of two particles. The classification of all such geodesics on the basis of the proved theorem for extremal spherical orbits is given. Case of the unlimited...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1503.04289
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4.0
Jun 29, 2018
06/18
by
A. A. Grib; Yu. V. Pavlov
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eye 4
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We study properties of particles with zero or negative energy and a nonzero orbital angular momentum in the ergosphere of a rotating black hole. We show that the sign of the particle energy is uniquely determined by the angular velocity of its rotation in the ergosphere. We give a simple proof of the fact that extreme black holes cannot exist. We investigate the question of the possibility of an unlimited energy increase in the center-of-mass system of two colliding particles, one or both of...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1601.02592
5
5.0
Jun 29, 2018
06/18
by
A. A. Grib; Yu. V. Pavlov
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eye 5
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A new feature of the rotating black holes is the existence in their ergosphere of trajectories of particles with negative and zero energies. Here we analyze general properties of such trajectories comparing them with usual trajectories of particles with positive energy. A comparison with the situation in rotating coordinate frame in Minkowski space-time is made. The possibility of the unbounded growth of the energy of two colliding particles in the centre of mass frame in the ergosphere is...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1607.02729
4
4.0
Jun 30, 2018
06/18
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A. A. Hakobyan; T. A. Nazaryan; V. Zh. Adibekyan; A. R. Petrosian; L. S. Aramyan; D. Kunth; G. A. Mamon; V. de Lapparent; E. Bertin; J. M. Gomes; M. Turatto
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eye 4
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We present an analysis of the relative frequencies of different supernova (SN) types in spirals with various morphologies and in barred or unbarred galaxies. We use a well-defined and homogeneous sample of spiral host galaxies of 692 SNe from the Sloan Digital Sky Survey in different stages of galaxy-galaxy interaction and activity classes of nucleus. We propose that the underlying mechanisms shaping the number ratios of SNe types can be interpreted within the framework of interaction-induced...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1407.6896
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8.0
Jun 27, 2018
06/18
by
A. A. Kirillov; E. P. Savelova
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eye 8
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We suggest a new scenario in which the Universe starts its evolution with a fractal topological structure. This structure is described by a gas of wormholes. It is shown that the polarization of such a gas in external fields possesses a spatial dispersion, which results in a modification of the Newton's law. The dependence on scales is determined by the distribution of distances between throat ends. The observed in galaxies logarithmic correction confirms that the distribution has fractal...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1505.05101
3
3.0
Jun 30, 2018
06/18
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A. A. Kirillov; E. P. Savelova
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eye 3
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We model spacetime foam by a gas of virtual wormholes. For a free scalar field we derive the effective Lagrangian which accounts for the interaction with spacetime foam and contains two additional non-local terms. One term describes the scattering of scalar particles on virtual wormholes and explicitly reproduces the Pauli-Villars regularization procedure. The second term describes the back reaction of particles on the number density of wormholes and introduces a self-interaction between...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1405.5074
3
3.0
Jun 28, 2018
06/18
by
A. A. Kirillov; E. P. Savelova
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eye 3
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We describe in details the procedure how the Lobachevsky space can be factorized to a space of the constant negative curvature filled with a gas of wormholes. We show that such wormholes have throat sections in the form of tori and are traversable and stable in the cosmological context. The relation of such wormholes to the dark matter phenomenon is briefly described. We also discuss the possibility of the existence of analogous factorizations for all types of homogeneous spaces.
Topics: Cosmology and Nongalactic Astrophysics, Astrophysics, General Relativity and Quantum Cosmology,...
Source: http://arxiv.org/abs/1512.01450
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12
Jun 27, 2018
06/18
by
A. A. Kirillov; E. P. Savelova
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eye 12
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The problem of scattering of CMB radiation on wormholes is considered. It is shown that a static gas of wormholes does not perturb the spectrum of CMB. In the first order by $v/c$ the presence of peculiar velocities gives rise to the dipole contribution in $\Delta T/T$, which corresponds to the well-known kinetic Sunyaev-Zel'dovich effect. In next orders there appears a more complicated dependence of the perturbed CMB spectrum on peculiar velocities. We also discuss some peculiar features of...
Topics: General Relativity and Quantum Cosmology, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1505.05952
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3.0
Jun 29, 2018
06/18
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A. A. Kobtsev; V. D. Ivashchuk; K. K. Ernazarov
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eye 3
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A D-dimensional gravitational model with Gauss-Bonnet and cosmological term is considered. When ansatz with diagonal cosmological metrics is adopted, we overview recent solutions for zero cosmological term and find new examples of solutions for non-zero cosmological term and D = 8 with exponential dependence of scale factors which describe an expansion of our 3-dimensional factor-space and contraction of 4-dimensional internal space.
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1602.05594
5,020
5.0K
Dec 9, 2015
12/15
by
A. A. Logunov, M. A. Mestvirishvili
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eye 5,020
favorite 18
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The gravitational field is constructed as a physical field in the spirit of Faraday and Maxwell, and this field has energy, momentum, and spins 2 and 0. In this post we see book titled The Relativistic Theory of Gravitation by A. A. Logunov and M. A. Mestvirishvili. If you think the title is a bit scary, then it is. Without a proper background in General Relativity (GR) and associated subjects (tensor calculus, etc.) this book is not readable. The topics are mostly at advanced level and already...
Topics: cosmology, einstein, equivalence principle, general relativity, geodesics, gravitational waves, mir...
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3.0
Jun 30, 2018
06/18
by
A. A. Saharian; V. F. Manukyan
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eye 3
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We evaluate the positive-frequency Wightman function, the vacuum expectation values (VEVs) of the field squared and the energy-momentum tensor for a massive scalar field with general curvature coupling for a cylindrical shell in background of dS spacetime. The field is prepared in the Bunch-Davies vacuum state and on the shell the corresponding operator obeys Robin boundary condition. In the region inside the shell and for non-Neumann boundary conditions, the Bunch-Davies vacuum is a physically...
Topics: Quantum Physics, High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1406.0393
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2.0
Jun 29, 2018
06/18
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A. A. Saharian; V. F. Manukyan; N. A. Saharyan
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eye 2
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Complete set of cylindrical modes is constructed for the electromagnetic field inside and outside a cylindrical shell in the background of $(D+1)$% -dimensional dS spacetime. On the shell, the field obeys the generalized perfect conductor boundary condition. For the Bunch-Davies vacuum state, we evaluate the expectation values (VEVs) of the electric field squared and of the energy-momentum tensor. The shell-induced contributions are explicitly extracted. In this way, for points away from the...
Topics: High Energy Physics - Theory, Astrophysics, Cosmology and Nongalactic Astrophysics, General...
Source: http://arxiv.org/abs/1604.06244
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7.0
Jun 30, 2018
06/18
by
A. A. Sheykin; D. A. Grad; S. A. Paston
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eye 7
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We study the explicit embeddings of static black holes. We obtain two new minimal embeddings of the Schwarzchild-de Sitter metric which smoothly cover both horizons of this metric. The lines of time for these embeddings are more complicated than hyperbolas. Also we shortly discuss the possibility of using non-hyperbolic embeddings for calculation of the black hole Hawking temperature in the Deser and Levin approach.
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1401.7820
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3.0
Jun 30, 2018
06/18
by
A. A. Sheykin; S. A. Paston
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eye 3
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We study the approach to gravity in which our curved spacetime is considered as a surface in a flat ambient space of higher dimension (the embedding theory). The dynamical variable in this theory is not a metric but an embedding function. The Euler-Lagrange equations for this theory (Regge-Teitelboim equations) are more general than the Einstein equations, and admit "extra solutions" which do not correspond to any Einsteinian metric. The Regge-Teitelboim equations can be explicitly...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1402.1121
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2.0
Jun 28, 2018
06/18
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A. A. Sheykin; S. A. Paston
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eye 2
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This paper is devoted to the approach to gravity as a theory of a surface embedded in a flat ambient space. After the brief review of the properties of original theory by Regge and Teitelboim we concentrate on its field-theoretic reformulation, which we call splitting theory. In this theory embedded surfaces are defined through the constant value surfaces of some set of scalar fields in high-dimensional Minkowski space. We obtain an exact expressions for this scalar fields in the case of...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1511.09268
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5.0
Jun 30, 2018
06/18
by
A. A. Sheykin; S. A. Paston
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eye 5
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Theory of gravity is considered in the Regge-Teitelboim approach in which the pseudo-Riemannian space is treated as a surface isometrically embedded in an ambient Minkowski space of higher dimension. This approach is formulated in terms of a field theory in which the original pseudo-Rimannian space is defined by the field constant-value surfaces. The symmetry properties of the proposed theory are investigated, and possible structure of the field-theoretical Lagrangian is discussed.
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1704.06883
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7.0
Jun 28, 2018
06/18
by
A. A. Sheykin; S. A. Paston
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eye 7
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We consider the problem of the existence of global embeddings of metrics of spherically symmetric black holes into an ambient space with the minimal possible dimension. We classify the possible types of embeddings by the type of realization of the metric symmetry by ambient space symmetries. For the Schwarzschild, Schwarzschild-de Sitter, and Reissner-Nordstrom black holes, we prove that the known global embeddings are the only ones. We obtain a new global embedding for the...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1512.08280
2
2.0
Jun 29, 2018
06/18
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A. A. Stupka
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eye 2
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Because of absence of time derivatives from scalar potential as a generalized coordinate of gravitation field (GF) in action of nonrelativistic gravitating system, application of the Hamilton method for description of GF mechanics was impossible. In the paper a transformation of the generalized coordinate of GF, that is based on continuity equation and minimal action principle, is proposed. A potential vector is introduced that is similar to fixing of Hamilton gauge of the electromagnetic...
Topics: Statistical Mechanics, Condensed Matter, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1603.00829
3
3.0
Jun 30, 2018
06/18
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A. A. Williams; N. W. Evans
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eye 3
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We provide a family of action-based distribution functions (DFs) for the double-power law family of densities often used to model galaxies. The DF itself is a double-power law in combinations of the actions, and reduces to the known limits in the case of a pure power-law at small and large radii. Our method enables the velocity anisotropy of the model to be tuned, and so the anisotropy in the inner and outer parts can be specified for the application in hand. We provide self-consistent DFs for...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1412.4640
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6.0
Jun 29, 2018
06/18
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A. A. Zheltukhin
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eye 6
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Phenomenological Lagrangians for physical systems with spontaneously broken symmetries are reformulated in terms of gauge field theory. Description of the Dirac $p$-branes in terms of the Yang-Mills-Cartan gauge multiplets interacting with gravity, is proved to be equivalent to their description as a closed dynamical system with the symmetry $ISO(1,D-1)$ spontaneously broken to $ISO(1,p)\times SO(D-p-1)$.
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1604.00694
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15
Jun 27, 2018
06/18
by
A. Abdolmaleki; T. Najafi
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eye 15
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Modified gravity and generalized second law (GSL) of thermodynamics are interesting topics in the modern cosmology. In this regard, we investigate the GSL of gravitational thermodynamics in the framework of modified Gauss-Bonnet gravity or f(G)-gravity. We consider a spatially FRW universe filled with the matter and radiation enclosed by the dynamical apparent horizon with the Hawking temperature. For two viable f(G) models, we first numerically solve the set of differential equations governing...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1504.03544
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5.0
Jun 30, 2018
06/18
by
A. Abdolmaleki; T. Najafi; K. Karami
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Within the context of scalar-tensor gravity, we explore the generalized second law (GSL) of gravitational thermodynamics. We extend the action of ordinary scalar-tensor gravity theory to the case in which there is a non-minimal coupling between the scalar field and the matter field (as chameleon field). Then, we derive the field equations governing the gravity and the scalar field. For a FRW universe filled only with ordinary matter, we obtain the modified Friedmann equations as well as the...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1401.7549
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4.0
Jun 28, 2018
06/18
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A. Agarwal; A. C. Gupta
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eye 4
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To search for optical variability on a wide range of timescales, we have carried out photometric monitoring of 3C 454.3, 3C 279 and S5 0716+714. CCD magnitudes in B, V, R and I pass-bands were determined for $\sim$ 7000 new optical observations from 114 nights made during 2011 - 2014, with an average length of $\sim$ 4 h each, at seven optical telescopes. We measured multiband optical flux and colour variations on diverse timescales. We also investigated its spectral energy distribution using...
Topics: Astrophysics, Cosmology and Nongalactic Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1510.03383
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Jun 26, 2018
06/18
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A. Aghamohammadi; A. Mohammadi; T. Golanbari; Kh. Saaidi
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eye 17
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Tachyon inflation is reconsidered by using the recent observational data obtained from Planck-2013 and BICEP2. The Hamilton-Jacobi formalism is picked out as a desirable approach in this work, which allows one to easily obtain the main parameters of the model. The Hubble parameter is supposed as a power-law and exponential function of the scalar field, and each case is considered separately. The constraints on the model, which come from observational data, are explained during the work. The...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1502.07578
3
3.0
Jun 30, 2018
06/18
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A. Agnello; N. W. Evans; A. J. Romanowsky; J. P. Brodie
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eye 3
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We study the Globular Cluster (GC) system of the nearby elliptical galaxy M87 using the newly available dataset with accurate kinematics (Strader et al.2011). We find evidence for three distinct sub-populations of GCs in terms of colours, kinematics and radial profiles. We show that a decomposition into three populations (blue, intermediate and red GCs) is statistically preferred to one with two or four populations, and relate them to the stellar profile. We exploit the sub-populations to...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1401.4461
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4.0
Jun 30, 2018
06/18
by
A. Aguayo-Ortiz; S. Mendoza; D. Olvera
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eye 4
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In this article we develop a Primitive Variable Recovery Scheme (PVRS) to solve any system of coupled differential conservative equations in such a way that the obtained solution is the primitive variable vector and not the charge vector as is traditionally done. The article is presented bearing in mind special relativistic hydrodynamic numerical schemes using a pedagogical view in order to easily comprehend the PVRS. We present the convergence of the method for standard shock-tube problems of...
Topics: General Relativity and Quantum Cosmology, Physics, Astrophysics, Fluid Dynamics, High Energy...
Source: http://arxiv.org/abs/1704.00724
3
3.0
Jun 29, 2018
06/18
by
A. Aguilar-Arevalo; D. Amidei; X. Bertou; M. Butner; G. Cancelo; A. Castañeda Vázquez; B. A. Cervantes Vergara; A. E. Chavarria; C. R. Chavez; J. R. T. de Mello Neto; J. C. D'Olivo; J. Estrada; G. Fernandez Moroni; R. Gaïor; Y. Guandincerri; K. P. Hernández Torres; F. Izraelevitch; A. Kavner; B. Kilminster; I. Lawson; A. Letessier-Selvon; J. Liao; J. Molina; J. R. Peña; P. Privitera; K. Ramanathan; Y. Sarkis; T. Schwarz; C. Sengul; M. Settimo; M. Sofo Haro; R. Thomas; J. Tiffenberg; E....
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We present results of a dark matter search performed with a 0.6 kg day exposure of the DAMIC experiment at the SNOLAB underground laboratory. We measure the energy spectrum of ionization events in the bulk silicon of charge-coupled devices down to a signal of 60 eV electron equivalent. The data are consistent with radiogenic backgrounds, and constraints on the spin-independent WIMP-nucleon elastic-scattering cross section are accordingly placed. A region of parameter space relevant to the...
Topics: High Energy Physics - Phenomenology, Cosmology and Nongalactic Astrophysics, Instrumentation and...
Source: http://arxiv.org/abs/1607.07410
3
3.0
Jun 29, 2018
06/18
by
A. Aguilar-Arevalo; D. Amidei; X. Bertou; M. Butner; G. Cancelo; A. Castañeda Vázquez; B. A. Cervantes Vergara; A. E. Chavarria; C. R. Chavez; J. R. T. de Mello Neto; J. C. D'Olivo; J. Estrada; G. Fernandez Moroni; R. Gaïor; Y. Guardincerri; K. P. Hernández Torres; F. Izraelevitch; A. Kavner; B. Kilminster; I. Lawson; A. Letessier-Selvon; J. Liao; A. Matalon; V. B. B. Mello; J. Molina; P. Privitera; K. Ramanathan; Y. Sarkis; T. Schwarz; M. Settimo; M. Sofo Haro; R. Thomas; J. Tiffenberg; E....
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We present direct detection constraints on the absorption of hidden-photon dark matter with particle masses in the range 1.2-30 eV$c^{-2}$ with the DAMIC experiment at SNOLAB. Under the assumption that the local dark matter is entirely constituted of hidden photons, the sensitivity to the kinetic mixing parameter $\kappa$ is competitive with constraints from solar emission, reaching a minimum value of 2.2$\times$$10^{-14}$ at 17 eV$c^{-2}$. These results are the most stringent direct detection...
Topics: Astrophysics, High Energy Physics - Phenomenology, Cosmology and Nongalactic Astrophysics, High...
Source: http://arxiv.org/abs/1611.03066
3
3.0
Jun 30, 2018
06/18
by
A. Anastasiou; L. Borsten; M. J. Duff; L. J. Hughes; S. Nagy
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By regarding gravity as the convolution of left and right Yang-Mills theories together with a spectator scalar field in the bi-adjoint representation, we derive in linearised approximation the gravitational symmetries of general covariance, p-form gauge invariance, local Lorentz invariance and local supersymmetry from the flat space Yang-Mills symmetries of local gauge invariance and global super-Poincar\'e. As a concrete example we focus on the new-minimal (12+12) off-shell version of simple...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1408.4434
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Jun 27, 2018
06/18
by
A. Araujo; H. Jennen; J. G. Pereira; A. C. Sampson; L. L. Savi
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As quotient spaces, Minkowski and de Sitter are fundamental, non-gravitational spacetimes for the construction of physical theories. When general relativity is constructed on a de Sitter spacetime, the usual Riemannian structure is replaced by a more general structure called de Sitter-Cartan geometry. In the contraction limit of an infinite cosmological term, the de Sitter-Cartan spacetime reduces to a singular, flat, conformal invariant four-dimensional cone spacetime, in which our ordinary...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1503.05005
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Jun 28, 2018
06/18
by
A. Araujo; J. G. Pereira
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As quotient spaces, Minkowski and de Sitter are fundamental spacetimes in the sense that they are known "a priori", independently of Einstein equation. They represent different non-gravitational backgrounds for the construction of physical theories. If general relativity is constructed on a de Sitter spacetime, the underlying kinematics will no longer be ruled by Poincar\'e, but by the de Sitter group. In this case the definition of diffeomorphism changes, producing concomitant...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1506.06948
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3.0
Jun 30, 2018
06/18
by
A. Ashoorioon; M. M. Sheikh-Jabbari
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In view of the recent BICEP2 results [arXiv:1403.3985] which may be attributed to the observation of B-modes polarization of the CMB with tensor-to-scalar ratio $r=0.2_{-0.05}^{+0.07}$, we revisit M-flation model. Gauged M-flation is a string theory motivated inflation model with Matrix valued scalar inflaton fields in the adjoint representation of a $U(N)$ Yang-Mills theory. In continuation of our previous works, we show that in the M-flation model induced from a supersymmetric 10d background...
Topics: High Energy Physics - Theory, High Energy Physics - Phenomenology, Astrophysics, General Relativity...
Source: http://arxiv.org/abs/1405.1685
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7.0
Jun 28, 2018
06/18
by
A. Avgoustidis; R. T. Génova-Santos; G. Luzzi; C. J. A. P. Martins
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The redshift dependence of the cosmic microwave background temperature is one of the key cosmological observables. In the standard cosmological model one has $T(z)=T_0(1+z)$, where $T_0$ is the present-day temperature. Deviations from this behavior would imply the presence of new physics. Here we discuss how the combination of all currently available direct and indirect measurements of $T(z)$ constrains the common phenomenological parametrization $T(z)=T_0(1+z)^{1-\beta}$, and obtain the first...
Topics: Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1511.04335
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2.0
Jun 30, 2018
06/18
by
A. Azizi; M. Amiri
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In this paper, the ``massless" spin-$\frac{3}{2}$ fields in the de Sitter space are considered. This work is in the continuation of a previous paper devoted to the quantization of the de Sitter ``massive" spin-$\frac{3}{2}$ fields. Due to the appearance of gauge invariance and indefinite metric, the covariant quantization of the ``massless" spin-$\frac{3}{2}$ fields requires an indecomposable representation of the de Sitter group. The gauge fixing corresponding to the simplest...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1401.6381
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5.0
Jun 30, 2018
06/18
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A. B Balantekin; J. Carlson; D. J. Dean; G. M. Fuller; R. J. Furnstahl; M. Hjorth-Jensen; R. V. F. Janssens; Bao-An Li; W. Nazarewicz; F. M. Nunes; W. E. Ormand; S. Reddy; B. M. Sherrill
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The Facility for Rare Isotope Beams (FRIB) will be a world-leading laboratory for the study of nuclear structure, reactions and astrophysics. Experiments with intense beams of rare isotopes produced at FRIB will guide us toward a comprehensive description of nuclei, elucidate the origin of the elements in the cosmos, help provide an understanding of matter in neutron stars, and establish the scientific foundation for innovative applications of nuclear science to society. FRIB will be essential...
Topics: Astrophysics, Astrophysics of Galaxies, Cosmology and Nongalactic Astrophysics, Nuclear Experiment,...
Source: http://arxiv.org/abs/1401.6435
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6.0
Jun 30, 2018
06/18
by
A. B. Arbuzov; B. N. Latosh
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Quantum behavior of the John Lagrangian from the Fab Four class of Covariant Galileons is stud- ied. We consider one-loop corrections to the John interaction due to cubic scalar field interactions. Counter Terms are calculated, one of them belongs to the Fab Four class, the other one to Covariant Galileons. The role of quantum corrections in context of cosmological applications is discussed.
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1703.06626
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8.0
Jun 29, 2018
06/18
by
A. B. Balantekin
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For a long time very little experimental information was available about neutrino properties, even though a minute neutrino mass has intriguing cosmological and astrophysical implications. This situation has changed in recent decades: intense experimental activity to measure many neutrino properties took place. Some of these developments and their implications for astrophysics and cosmology are briefly reviewed with a particular emphasis on neutrino magnetic moments and collective neutrino...
Topics: Astrophysics, High Energy Physics - Phenomenology, Cosmology and Nongalactic Astrophysics, Nuclear...
Source: http://arxiv.org/abs/1609.02207
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Jun 27, 2018
06/18
by
A. B. Barreto; T. S. Almeida; C. Romero
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In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+1)-dimensional form. We next write the Lagrangian of the gravitation field based in Weyl-type gravity theory. We extend the general relativistic formalism in such a way that it can be applied to investigate the quantum...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1503.08455
