Model for a time-dependent cosmological constant

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

Coasting Cosmologies with Time Dependent Cosmological Constant

The effect of a time dependent cosmological constant is considered in a family of scalartensor theories. FriedmannRobertsonWalker cosmological models for vacuum and perfect fluid matter are found. They have a linear expansion factor, the so called coasting cosmology, the gravitational ”constant” decreases inversely with time; that is these models satisfy the Dirac Hypotheses. The cosmological ”...

متن کامل

Gauge-dependent cosmological 'constant'

When the cosmological constant of spacetime is derived from the 5D inducedmatter theory of gravity, we show that a simple gauge transformation changes it to a variable measure of the vacuum which is infinite at the big bang and decays to an astrophysically acceptable value at late epochs. We outline implications of this for cosmology and galaxy formation. PACS numbers: 04.20.Cv, 04.50.+h, 98.62...

متن کامل

A new cosmological constant model

We propose a new cosmological model with a time-dependent cosmological constant (Λ ∝ 1/t), which starting at the Planck time as ΛP l ∼ M P l, evolves to the present-day allowed value of Λ0 ∼ 10M P l. This scenario is supported by non-critical string theory considerations. We compute the age of the Universe and the time-dependence of the scale factor in this model, and find general agreement wit...

متن کامل

The Cosmon Model for an Asymptotically Vanishing Time-dependent Cosmological “constant”

We investigate the coupled system of gravity and a scalar with exponential potential. The energy momentum tensor of the scalar field induces a time-dependent cosmological “constant”. This adjusts itself dynamically to become in the “late” universe (including today) proportional to the energy density of matter and radiation. Possible consequences for the present cosmology are shortly discussed. ...

متن کامل

Naturally Time Dependent Cosmological Constant in String Theory

In the light of the proposal of Ref. [1], we discuss in detail the issue of the cosmological constant, explaining how can string theory naturally predict the value which is experimentally observed, without low-energy supersymmetry. e-mail: [email protected]

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: Classical and Quantum Gravity

سال: 2001

ISSN: 0264-9381,1361-6382

DOI: 10.1088/0264-9381/18/7/309