Cosmological Dynamics from Modified f(R) Gravity in Einstein Frame

نویسنده

  • Daris Samart
چکیده

In this paper, we investigate and analyze the cosmological dynamics of the universe, with an effect of modified f(R) gravity emerging at cosmological scale. We choose the Einstein frame as a physical frame. We consider phase portraits of the universe at the late time from modified f(R) gravity model. This result gives our universe an acceleration phase expansion without introducing existence of dark energy dominating our universe. PACS numbers: 04.50.+h, 98.80.-k

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Some aspects of the cosmological conformal equivalence between “Jordan Frame” and “Einstein Frame”

The conformal equivalence between Jordan frame and Einstein frame can be used in order to search for exact solutions in general theories of gravity in which scalar fields are minimally or nonminimally coupled with geometry. In the cosmological arena a relevant role is played by the time parameter in which dynamics is described. In this paper we discuss such issues considering also if cosmologic...

متن کامل

Cosmological Acceleration: Dark Energy or Modified Gravity?

The recently observed accelerating cosmological expansion or ”dark energy” may be either a negative pressure constituent in General Relativity (Dark Energy) or modified gravity (Dark Gravity) without any constituent Dark Energy. Lowor high-curvature modifications of Einstein gravity are distinguished by the spacetime (Ricci) curvature of their vacua. If constituent Dark Energy does not exist, s...

متن کامل

Stability of Palatini-f(R) cosmology

The evolution of linear cosmological perturbations in modified theories of gravity is investigated assuming the Palatini formalism. It has been discussed about the stability problem in this model based on the equivalence between f(R) gravity and the scalar tensor theory. However, we study this problem in the physical frame where the matter is minimally coupled. In general, the stability of the ...

متن کامل

دسته‌ای از جوابهای دقیق گرانش با مشتقات بالاتر در چهار بعد

 In this paper we consider the action of higher derivative gravity up to the second order terms in the scalars made from the Ricci scalar, Ricci and Riemann tensors. We use the Bach- Lanczos identity of the Weyl tensor in four dimensions and show that the solutions of 4-dimensional Einstein equations with cosmological constant term in vacuum, which are known as Einstein metrics, satisfy the fie...

متن کامل

Acceleration from Modified Gravity: Lessons from Worked Examples

I examine how two specific examples of modified gravity explanations of cosmic acceleration help us understand some general problems confronting cosmological tests of gravity: how do we distinguish modified gravity from dark energy if they can be made formally equivalent? how do we parameterize deviations according to physical principles with sufficient generality, yet focus cosmological tests ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2006