Big-bang nucleosynthesis in Brans-Dicke cosmology with a varying Λ term related to WMAP

نویسندگان

  • R. Nakamura
  • K. Arai
چکیده

We investigate the big-bang nucleosynthesis in a Brans-Dicke model with a varying Λ term using the Monte-Carlo method and likelihood analysis. It is found that the cosmic expansion rate differs appreciably from that of the standard model. The produced abundances of He, D, and barely Li are consistent with the observed ones within the uncertainties in nuclear reaction rates when the baryon to photon ratio η = (5.47 − 6.64)×10, which is in agreement with the value deduced from WMAP.

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

Nucleosynthesis constraints on an extended Jordan-Brans-Dicke theory.

In a natural extension of the Jordan{Brans{Dicke theory the scalar eld can couple much more strongly to dark than to visible matter. New limits on the coupling constants of the model are obtained from standard big{bang nucleosynthesis.

متن کامل

Einstein-Brans-Dicke Cosmology

We studied the Einstein-Brans-Dicke cosmology in detail. The difference of the evolution of the universe is significant between Einstein-Brans-Dicke cosmology and standard big-bang model during the radiation-dominated era. The power-law evolution of the scale factor is fast enough to solve the cosmological puzzles and slow enough to avoid the graceful exit problem. However, the constraints from...

متن کامل

Age of the universe constrained from the primordial nucleosynthesis in the Brans-Dicke theory with a varying cosmological term

The age of the universe is investigated from a viewpoint of the primordial nucleosynthesis in the Brans-Dicke model with a varying Λ term. It is shown that the age can be long enough compared with that of the globular clusters using two critical quantities recently reported from the HST observations: the Hubble constant, and deuterium abundances. Then it is shown that the present rate of variat...

متن کامل

Primordial Nucleosynthesis in Light of WMAP

Big bang nucleosynthesis has long provided the primary determination of the cosmic baryon density ΩBh , or equivalently the baryon-to-photon ratio, η. Recently, data on CMB anisotropies have become increasingly sensitive to η. The comparison of these two independent measures provides a key test for big bang cosmology. The first release of results from the Wilkinson Microwave Anisotropy Probe (W...

متن کامل

Big–bang Nucleosynthesis as a Probe of the Geometry of Superspace

We study the effect from a general ultralocal supermetric on primordial nucleosynthesis for Friedmann-Robertson-Walker Cosmology. The parameter λ of the supermetric changes the effective number of degrees of freedom, g∗, which modifies the Friedmann equation. This modification produces variations in the production of primordial 4He. The observations of the primordial abundances of light element...

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 2005