Accelerating cosmologies from non-local higher-derivative gravity

نویسندگان
چکیده

برای دانلود باید عضویت طلایی داشته باشید

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

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Accelerating Cosmologies from S-Branes

We point out that the recently proposed model of a flat 4-dimensional universe with accelerated expansion in string/M-theory is a special case of time-dependent solutions that the author found under the name of “S-branes.” We also show that similar accelerating models can be obtained from S-branes if the internal space is chosen to be hyperbolic or flat spaces. PACS numbers: 04.50.+h, 11.25.Yb,...

متن کامل

Accelerating cosmologies from exponential potentials

It is learnt that exponential potentials of the form V ∼ exp(−2cφ/Mp) arising from the hyperbolic compactification of higher-dimensional theories are of interest for getting short periods of accelerated cosmological expansions. Using such a potential derived for the combined case of hyperbolic-flux compactification, we study a fourdimensional flat (or open) FRW cosmolgy and give analytic (and n...

متن کامل

Towards Inflation and Accelerating Cosmologies in String-Generated Gravity Models

The string α′-correction to the usual Einstein action comprises a Gauss-Bonnet integrand multiplied by non-trivial functions of the modulus field χ and/or the dilaton field φ. We discuss how the presence of such terms in the four dimensional effective action can explain several novel phenomena, such as a four-dimensional flat Friedmann-Robertson-Walker universe undergoing a cosmic inflation at ...

متن کامل

Super-accelerating bouncing cosmology in asymptotically free non-local gravity

Recently, evidence has been collected that a class of gravitational theories with certain non-local operators is renormalizable. We consider one such model which, at the linear perturbative level, reproduces the effective non-local action for the light modes of bosonic closed string-field theory. Using the property of asymptotic freedom in the ultraviolet and fixing the classical behavior of th...

متن کامل

Higher Derivative Gravity from the Universal Renormalization Group Machine

We study the renormalization group flow of higher derivative gravity, utilizing the functional renormalization group equation for the average action. Employing a recently proposed algorithm, termed the universal renormalization group machine, for solving the flow equation, all the universal features of the one-loop beta-functions are recovered. While the universal part of the beta-functions adm...

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

ژورنال

عنوان ژورنال: Physics Letters B

سال: 2009

ISSN: 0370-2693

DOI: 10.1016/j.physletb.2008.11.060