Velocity-dependent forces and an accelerating universe

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

Tring Theory and an Accelerating Universe

An accelerating Universe can be accommodated naturally within non-critical string theory, in which scattering is described by a superscattering matrix $ that does not factorize as a product of Sand S †-matrix elements and time evolution is described by a modified Liouville equation characteristic of open quantum-mechanical systems. We describe briefly alternative representations in terms of the...

متن کامل

Algorithmic regularization with velocity-dependent forces

Algorithmic regularization uses a transformation of the equations of motion such that the leapfrog algorithm produces exact trajectories for two-body motion as well as regular results in numerical integration of the motion of strongly interacting few-body systems. That algorithm alone is not sufficiently accurate and one must use the extrapolation method for improved precision. This requires th...

متن کامل

Tensorial Perturbations in an Accelerating Universe

We study tensorial perturbations (gravitational waves) in a universe with particle production (OSC). The background of gravitational waves produces a perturbation in the redshift observed from distant sources. The modes for the perturbation in the redshift(induced redshift) are calculated in a universe with particle production.

متن کامل

Growth index in an accelerating universe

We obtain the exact analytic form of growth index (f = Ωm(a) ) at present epoch in a flat universe with including the constant equation of state of dark energy (ωde). For the cosmological constant (ωde = −1) we obtain γ = 0.5547 which is very close to the well known value 6/11. However, if ωde = −0.9, then γ gives rise to 0.6405. Ω 0 m dependence of γ is fairly small for the viable range of the...

متن کامل

Scalar - tensor gravity in an accelerating universe

We consider scalar-tensor theories of gravity in an accelerating universe. The equations for the background evolution and the perturbations are given in full generality for any parametrization of the Lagrangian, and we stress that apparent singularities are sometimes artifacts of a pathological choice of variables. Adopting a phenomenological viewpoint, i.e., from the observations back to the t...

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: Nuclear Physics B

سال: 2002

ISSN: 0550-3213

DOI: 10.1016/s0550-3213(02)00285-7