13038

11915

كارشناسي ارشد

ذرات بنيادي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك

۱۳۹۶

X، 127ص.: مصور، جدول، عكس، نمودار

مسلم زارعي

بهروز ميرزا

ممتحن مدعو: احمد شيرزاد; ممتحن داخلي: صديقه سجاديان

1396/09/12

كتابنامه

فيزيك

فيزيك

ID11915

Measurement of Circular Polarization of Cosmic Microwave Background Sepideh Ghaziasgar Sepide ghaziasgar@ph iut ac ir June 17 2017 Department of Physics Isfahan University of Technology Isfahan 84156 83111 Iran University Code IUT 77142 Degree M Sc Language Farsi supervisor Dr Moslem Zarei M Zarei@cc iut ac ir Abstract This Study investigates the measurement of the circular polarization of the Cosmic Microwave Background CMB and those radiofrequency sources which generate circular polarization First briefly reviews the thermal history of the universe and the CMB physics CMB radiation is produced at the last scattering surface LSS which is the smoking gun of big bang model By measuring the fluctuations of the CMB one can study the physics of early universe As it is well known CMB can be polarized due to the Compton scattering and quadruple anisotropy at LSS It is usually assumed that CMB is linearly polarized However circular polarization is generally assumed for the CMB due to some new physics at LSS In this study the CMB polarization is parameterized using the Stokes parameters I Q U and V that I parameterize the intensity Q and U parameterize the linear polarization and V parameterize the circular polarization Recent measurements have shown that 10 percent of CMB radiation is linearly polarized The next chapter reviews and describes the polarization of radio sources such as M81 and SgrA Some radio observations have shown that M81 and SgrA involve small amount of cir cular polarization In this study different methods of detection of their circular polarization are reviewed Then to measure the CMB circular polarization some experiments were done Among these experiments the main focus is on the recent experiment is called SPIDER It is done to measure the circular polarization and discuss its recent constraints Finally the calculation of error on the Stokes pa rameters when the parameters were measured was done First it is assumed that there is no circular polarization It is shown how systematic errors can distort the observed CMB polarization Then the method is extended and considered the Stokes Parameter V It is shown how systematic effects can contaminate any future measurements of circular polarization Keywords Observational Cosmology Thermal History Stocks Parameters CMB Polarization Radiofrequency Sources Circular Polarization Measurements of circular polarization Spider Systematic Errors

مسلم زارعي

بهروز ميرزا

ممتحن مدعو: احمد شيرزاد; ممتحن داخلي: صديقه سجاديان