Results 11 to 20 of about 2,610 (79)
Mimetic Gravity: A Review of Recent Developments and Applications to Cosmology and Astrophysics
Advances in High Energy Physics, Volume 2017, Issue 1, 2017., 2017 Mimetic gravity is a Weyl‐symmetric extension of General Relativity, related to the latter by a singular disformal transformation, wherein the appearance of a dust‐like perfect fluid can mimic cold dark matter at a cosmological level. Within this framework, it is possible to provide a unified geometrical explanation for dark matter, the late‐time ...
Lorenzo Sebastiani +3 more
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Bose‐Einstein Condensate Dark Matter Halos Confronted with Galactic Rotation Curves
Advances in High Energy Physics, Volume 2017, Issue 1, 2017., 2017 We present a comparative confrontation of both the Bose‐Einstein Condensate (BEC) and the Navarro‐Frenk‐White (NFW) dark halo models with galactic rotation curves. We employ 6 High Surface Brightness (HSB), 6 Low Surface Brightness (LSB), and 7 dwarf galaxies with rotation curves falling into two classes.
M. Dwornik +4 more
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Dark Atoms and the Positron‐Annihilation‐Line Excess in the Galactic Bulge
Advances in High Energy Physics, Volume 2014, Issue 1, 2014., 2014 It was recently proposed that stable particles of charge −2, O−−, can exist and constitute dark matter after they bind with primordial helium in O‐helium (OHe) atoms. We study here in detail the possibility that this model provides an explanation for the excess of gamma radiation in the positron‐annihilation line from the galactic bulge observed by ...
J.-R. Cudell +3 more
wiley +1 more source
The Mitchell Spectrograph: Studying Nearby Galaxies with the VIRUS Prototype
Advances in Astronomy, Volume 2013, Issue 1, 2013., 2013 The Mitchell Spectrograph (a.k.a. VIRUS‐P) on the 2.7 m Harlan J. Smith telescope at McDonald Observatory is currently the largest field of view (FOV) integral field unit (IFU) spectrograph in the world (1.7′ × 1.7′). It was designed as a prototype for the highly replicable VIRUS spectrograph which consists of a mosaic of IFUs spread over a 16 ...
Guillermo A. Blanc +1 more
wiley +1 more source
A Scalar Field Dark Matter Model and Its Role in the Large‐Scale Structure Formation in the Universe
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 We present a model of dark matter based on scalar‐tensor theory of gravity. With this scalar field dark matter model we study the non‐linear evolution of the large‐scale structures in the universe. The equations that govern the evolution of the scale factor of the universe are derived together with the appropriate Newtonian equations to follow the ...
Mario A. Rodríguez-Meza, Dario Nuñez
wiley +1 more source
Advances in Astronomy, Volume 2010, Issue 1, 2010., 2010 We review numerical works carried out over the last decade on the role of environmental mechanisms in shaping nature of the faintest galaxies known, dwarf spheroidals (dSphs). The combination of tidally induced morphological transformation, termed tidal stirring, with mass loss due to tidal and ram‐pressure stripping aided by heating due to the cosmic ...
Lucio Mayer, Andrey V. Kravtsov
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Dark Matter Substructure and Dwarf Galactic Satellites
Advances in Astronomy, Volume 2010, Issue 1, 2010., 2010 A decade ago cosmological simulations of increasingly higher resolution were used to demonstrate that virialized regions of Cold Dark Matter (CDM) halos are filled with a multitude of dense, gravitationally bound clumps. These dark matter subhalos are central regions of halos that survived strong gravitational tidal forces and dynamical friction during
Andrey Kravtsov, Ulrich Hopp
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Kinematics of Milky Way Satellites: Mass Estimates, Rotation Limits, and Proper Motions
Advances in Astronomy, Volume 2010, Issue 1, 2010., 2010 In the past several years kinematic data sets from Milky Way satellite galaxies have greatly improved, furthering the evidence that these systems are the most dark matter dominated objects known. This paper discusses a maximum likelihood formalism that extracts important quantities from these kinematic data sets, including the amplitude of a rotational
Louis E. Strigari, Andrey V. Kravtsov
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Advances in Astronomy, Volume 2010, Issue 1, 2010., 2010 This paper gives an overview of the attempts to determine the distribution of dark matter in low surface brightness disk and gas‐rich dwarf galaxies, both through observations and computer simulations. Observations seem to indicate an approximately constant dark matter density in the inner parts of galaxies, while cosmological computer simulations ...
W. J. G. de Blok, Elias Brinks
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Dark Energy From the Gravitational Wave Background With Scalar Field Dark Matter
Astronomische Nachrichten, Volume 346, Issue 3-4, March-May 2025.ABSTRACT Recent observational results, such as those from pulsar timing arrays (PTA), suggest a low‐frequency Gravitational Wave Background (GWB) permeates our universe. This opens the possibility that gravitational waves could span a broader spectrum, potentially impacting cosmological scales.
Edwin L. Pérez‐Ochoa, Tonatiuh Matos
wiley +1 more source