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Related papers: Cosmic Fluctuations and Dark Matter from Scalar Fi…

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Ultra-light scalar fields may explain the nature of the dark matter in our universe. If such scalars couple quadratically to particles of the Standard Model the scalar acquires an effective mass which depends on the local matter energy…

High Energy Physics - Phenomenology · Physics 2026-03-04 Clare Burrage , Angus Macdonald , Michael P. Ross , Gray Rybka , Elisa Todarello

A wide range of large scale observations hint towards possible modifications on the standard cosmological model which is based on a homogeneous and isotropic universe with a small cosmological constant and matter. These observations, also…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-21 Leandros Perivolaropoulos

The new element of theory of galaxy formation, strong primordial inhomogeneities, is shown to be a reflection of unstable large scale structures of topological defects, created in second order phase transitions in the inflationary Universe.…

Astrophysics · Physics 2007-05-23 M. Yu. Khlopov , S. G. Rubin , A. S. Sakharov

Modular fluctuations have previously been shown to obey an area law $\langle \Delta K^2 \rangle = \langle K \rangle = {A}/{4 G_N}$. Furthermore, modular fluctuations generate fluctuations in the spacetime geometry of empty causal diamonds.…

High Energy Physics - Theory · Physics 2022-11-30 Erik Verlinde , Kathryn M. Zurek

Recent observations of magnetic fields in intergalactic void regions and in high redshift galaxies may indicate that large scale magnetic fields have a primordial origin. If primordial magnetic fields were present soon after the…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-27 Maresuke Shiraishi , Hiroyuki Tashiro , Kiyotomo Ichiki

We extend mass scale sequence to a mass tree. From mass tree, the evolution of the universe is described by three stages: chaos, inflation and expansion. The first two stages have c mutations and the inflation appears as a step by step…

General Physics · Physics 2020-05-06 Wuliang Huang , Xiaodong Huang

The conventional misalignment mechanism for scalar dark matter depends on the initial field value, which governs the oscillation amplitude and present-day abundance. We present a mechanism by which a feeble (Planck-suppressed) coupling of…

High Energy Physics - Phenomenology · Physics 2021-09-13 Brian Batell , Akshay Ghalsasi

Local measurements of the Hubble parameter obtained from the distance ladder at low redshift are in tension with global values inferred from cosmological standard rulers. A key role in the tension is played by the assumptions on the…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-12 Enis Belgacem , Tomislav Prokopec

We discuss the possible sources of dark matter axions in the early universe. In the standard thermal scenario, an axion string network forms at the Peccei-Quinn phase transition $T\sim \fa$ and then radiatively decays into a cosmological…

Astrophysics · Physics 2016-08-30 E. P. S. Shellard , R. A. Battye

Large self-gravitating stellar systems share with correlated liquids in condensed matter physics a pattern of hierarchical density variations. While it takes the microscopic time resolution to discern the correlated dynamics of the critical…

Astrophysics of Galaxies · Physics 2018-11-08 Alexander B. Kashuba

A sizable fraction of the total energy density of the universe may be in heavy particles with a net dark $U(1)'$ charge comparable to its mass. When the charges have the same sign the cancellation between their gravitational and gauge…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-23 Nemanja Kaloper , Antonio Padilla

First the fluctuation energy is derived from the adiabatic random fluctuations due to the second-order perturbation theory, and the evolutionary relation for it is expressed in the form of rho_f = rho_f (rho), where rho and rho_f are the…

General Relativity and Quantum Cosmology · Physics 2017-09-12 Kenji Tomita

The distribution of dark matter around galactic or cluster halos has usually been assumed to be approximately isothermal with a non-zero core radius, which is expected to be of the order of the size of the visible matter distribution.…

Astrophysics · Physics 2009-10-22 Ricardo A. Flores , Joel R. Primack

In the last time the cold dark matter (CDM) model has suggested more and more that it is not able to describe all the properties of nearby galaxies that can be observed in great detail as well as that it has some problems in the mechanism…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Juan Magaña , Tonatiuh Matos , Victor Robles , Abril Suárez

The amplitude of the pseudoscalar (axion) or scalar field fluctuates on a time scale of order of million field oscillation periods which is a typical coherence time in the virialized axion galactic dark matter halo model. This causes…

High Energy Physics - Phenomenology · Physics 2023-09-15 V. V. Flambaum , I. B. Samsonov

Primordial Black Holes (PBHs) might have formed in the early Universe due to the collapse of density fluctuations. PBHs may act as the sources for some of the gravitational waves recently observed. We explored the formation scenarios of…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-06 J. L. G. Sobrinho , P. Augusto

The definition of matter states on spacelike hypersurfaces of a 1+1 dimensional black hole spacetime is considered. Because of small quantum fluctuations in the mass of the black hole, the usual approximation of treating the gravitational…

High Energy Physics - Theory · Physics 2007-05-23 Miguel E. Ortiz

The degree of linear polarization has recently been found to show wide random variations over the solar disk. These variations are presumably at least partly due to fluctuations in the flux density of turbulent photospheric magnetic fields…

Astrophysics · Physics 2007-05-23 K. Petrovay

The emergence of Hawking radiation from vacuum fluctuations is analyzed in conventional field theories and their energy content is defined through the Aharonov weak value concept. These fluctuations travel in flat space-time and carry…

General Relativity and Quantum Cosmology · Physics 2010-04-06 F. Englert , S. Massar , R. Parentani