Zobrazeno 1 - 10
of 125
pro vyhledávání: '"Opher, Reuven"'
Autor:
Opher, Reuven
I discuss some of the most outstanding challenges in relativistic astrophysics in the subjects of: compact objects (Black Holes and Neutron Stars); dark sector (Dark Matter and Dark Energy); plasma astrophysics (Origin of Jets, Cosmic Rays and Magnet
Externí odkaz:
http://arxiv.org/abs/1305.2991
Publikováno v:
MNRAS, 415, 2969 (2011)
Some observations of galaxies, and in particular dwarf galaxies, indicate a presence of cored density profiles in apparent contradiction with cusp profiles predicted by dark matter N-body simulations. We constructed an analytical model, using particl
Externí odkaz:
http://arxiv.org/abs/1104.2850
Publikováno v:
Phys.Rev.D82:023501,2010
A smooth inflaton potential is generally assumed when calculating the primordial power spectrum, implicitly assuming that a very small oscillation in the inflaton potential creates a negligible change in the predicted halo mass function. We show that
Externí odkaz:
http://arxiv.org/abs/1006.2159
Publikováno v:
Monthly Notices of the Royal Astronomical Society, Volume 410, Issue 4, pp. 2149-2155 (2011)
We recently predicted the existence of random primordial magnetic fields (RPMF) in the form of randomly oriented cells with dipole-like structure with a cell size $L_0$ and an average magnetic field $B_0$. Here we investigate models for primordial ma
Externí odkaz:
http://arxiv.org/abs/1005.0639
Autor:
de Souza, Rafael S., Opher, Reuven
Publikováno v:
Astrophys. Space Sci. 2010, online first
It is generally assumed that the magnetic fields of millisecond pulsars (MSPs) are $\sim 10^{8}$G. We argue that this may not be true and the fields may be appreciably greater. We present six evidences for this: (1) The $\sim 10^{8}$ G field estimate
Externí odkaz:
http://arxiv.org/abs/1004.2976
Publikováno v:
Monthly Notices of the Royal Astronomical Society, Volume 406, Issue 1, pp. 482-485 (2010)
We investigate the impact of the existence of a primordial magnetic field on the filter mass, characterizing the minimum baryonic mass that can form in dark matter (DM) haloes. For masses below the filter mass, the baryon content of DM haloes are sev
Externí odkaz:
http://arxiv.org/abs/1003.2829
Autor:
de Souza, Rafael S., Opher, Reuven
Publikováno v:
Phys. Lett. B 705, 292 (2011)
The origin of magnetic fields in astrophysical objects is a challenging problem in astrophysics. Throughout the years, many scientists have suggested that non-minimal gravitational-electromagnetic coupling (NMGEC) could be the origin of the ubiquitou
Externí odkaz:
http://arxiv.org/abs/0804.4895
Publikováno v:
JCAP 0712:007,2007
We investigate the matter density fluctuations \delta\rho/\rho for two dark energy (DE) models in the literature in which the cosmological term \Lambda is a running parameter. In the first model, the running LCDM model, matter and DE exchange energy,
Externí odkaz:
http://arxiv.org/abs/0709.2130
Autor:
de Souza, Rafael S., Opher, Reuven
Publikováno v:
Phys.Rev.D77:043529,2008
(abridged) We suggest here that the large scale fields $\sim \mu$G, observed in galaxies at both high and low redshifts by Faraday Rotation Measurements (FRMs), have their origin in the electromagnetic fluctuations that naturally occurred in the dens
Externí odkaz:
http://arxiv.org/abs/astro-ph/0607181
Autor:
Opher, Reuven, Pelinson, Ana
Publikováno v:
Phys.Rev.D74:023505,2006
(abridged)We present a model which predicts inflation without the presence of inflaton fields, based on the \epsilon R^2 and Starobinsky models. It links the above models to the observable universe, in particular, to the ratio r of tensor to scalar f
Externí odkaz:
http://arxiv.org/abs/astro-ph/0512336