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Possibility of magnetic mass detection by the next generation of microlensing experiments
, Article Astrophysical Journal ; Volume 610, Issue 2 I , 2004 , Pages 673-678 ; 0004637X (ISSN) ; Habibi, F ; Sharif University of Technology
Institute of Physics Publishing
2004
Abstract
We study the possibility of magnetic mass detection using the gravitational microlensing technique. Recently, the theoretical effect of magnetic mass in NUT space on the microlensing light curve has been studied. It has been shown that in the low photometric signal-to-noise ratio and sampling rate of MACHO experiment light curves, no signature of the NUT factor has been found. In order to increase the sensitivity of magnetic mass detection, we propose a systematic search for microlensing events, using the currently running alert systems and complementary telescopes for monitoring Large Magellanic Clouds stars. This observation strategy provides the lowest observable limit of the NUT factor,...
Gravitational microlensing in NUT space
, Article Monthly Notices of the Royal Astronomical Society ; Volume 338, Issue 4 , 2003 , Pages 926-930 ; 00358711 (ISSN) ; Nouri Zonoz, M ; Sharif University of Technology
Blackwell Publishing Ltd
2003
Abstract
We study the theoretical signature of magnetic masses on the light curve of the gravitational microlensing effect in NUT space. The light curves for microlensing events in NUT space are presented and contrasted with those caused by lensing produced by normal matter. In the next step, associating the magnetic mass to the massive astrophysical compact halo objects (MACHOs), we try to see the effect on the light curves of microlensing candidates observed by the MACHO group. The presence or absence of this feature in the observed microlensing events can shed light on the question of the existence of magnetic masses in the Universe
Cosmological Observables in Past Light-Cone
, M.Sc. Thesis Sharif University of Technology ; Rahvar, Sohrab (Supervisor)
Abstract
One of the important concepts in cosmology is that all of the observations is done on the past light-cone. In general, cosmological linear perturbation theory is done in a particular gauge and often on spacelike hyperplanes. Then in order to link quantities calculated in perturbation theory with observables, we have to take into account effects coming from projecting these quantities onto past light-cone. We aim in this thesis to study these effects and to calculate corrections over observable quantities such as, two point correlation function and power spectrum of matter perturbations in cosmos. For a particular observational example, in the end we study clustering of structures in...
Particles in the early Universe: Interface of Cosmology and Particles Massive Neutrinos and Cosmology
, M.Sc. Thesis Sharif University of Technology ; Golshani, Mehdi (Supervisor) ; Farzan, Yasaman (Supervisor)
Abstract
Neutrino flavor oscillations are clear evidence of massive neutrinos. It has been for more than a decade that neutrino physics became one of active topics in the field of particle physics and various experiments started studying the flavor oscillation of neutrinos. Unfortunately, experiments studying the flavor oscillations are only sensitive to the mass square difference, and they are incapable of providing more information about the absolute mass scale of neutrinos. Additionally, sterile neutrinos having non-standard interactions are under vast investigations and studies. Determination of neutrino masses and their effective number is among the most challenging problems by which...