000			02785cam a2200325 a 4500
003			EG-GiCUC
005			20250223032018.0
008			180624s2017 ua f m 000 0 eng d
040			_aEG-GiCUC _beng _cEG-GiCUC
041	0		_aeng
049			_aDeposite
097			_aM.Sc
099			_aCai01.12.17.M.Sc.2017.Ma.I
100	0		_aMaha Salah Abdelmoneim
245	1	0	_aInflation in f(R) modified gravity / _cMaha Salah Abdelmoneim ; Supervised Ahmad A. Amer , Shaaban S. Khalil
260			_aCairo : _bMaha Salah Abdelmoneim , _c2017
300			_a68 P. ; _c25cm
502			_aThesis (M.Sc.) - Cairo University - Faculty of Science - Department of Mathematics
520			_aDespite some of its successful features, the standard big bang cosmology su{uFB00}ers from many problems. The Flatness and Horizon problems are two of its main un- solved problems. In{uFB02}ationary cosmology is an alternative framework to standard cosmology within which the in{uFB02}ation solves some of these problems e{uFB03}ciently. Many scenarios of in{uFB02}ation are invented. The original version of in{uFB02}ation was based on adding a scalar {uFB01}eld to the energy-momentum at the early Universe whose dynamics causes the in{uFB02}ation. Other alternatives depend on modifying the geometrical part of the general theory of relativity. The f(R) modi{uFB01}ed theory of gravity is one of the most straightforward generalizations of such examples. However f(R) serves again as the general relativity minimally coupled with a geometry-inspired scalar degree of freedom. In{uFB02}ation in f(R) theories is one of the active topics of research these days. In{uFB02}ation in the framework of f(R) modi{uFB01}ed gravity is revisited. We study the conditions that f(R) should satisfy in order to lead to a viable in{uFB02}ationary model in the original form and in the Einstein frame. Based on these criteria we propose a new logarithmic model as a potential candidate for f(R) theories aiming to de- scribe in{uFB02}ation consistent with observations from planck satellite (2015). The model predicts scalar spectral index 0.9615 <ns <0.9693 in agreement with observation and tensor-to-scalar ratio r of order 10-3. Furthermore, we show that for a class of models, a natural coupling between in{uFB02}ation and a scalar boson is generated through the minimal coupling between gravity and matter {uFB01}elds and a reheating temperature less that 109 GeV is obtained
530			_aIssued also as CD
653		4	_af(R)
653		4	_aInflation
653		4	_aModified gravity
700	0		_aAhmad A. Amer , _eSupervisor
700	0		_aShaaban S. Khalil , _eSupervisor
856			_uhttp://172.23.153.220/th.pdf
905			_aNazla _eRevisor
905			_aSamia _eCataloger
942			_2ddc _cTH
999			_c66619 _d66619