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Stable exponential cosmological solutions with zero variation of G and three different Hubble-like parameters in the Einstein–Gauss–Bonnet model with a \(\Lambda \) -term

. Ivashchuk 0 1 0 Center for Gravitation and Fundamental Metrology, VNIIMS , 46 Ozyornaya ul., Moscow 119361 , Russia 1 Institute of Gravitation and Cosmology, RUDN University , 6 Miklukho-Maklaya ul., Moscow

Stable exponential cosmological solutions with zero variation of G in the Einstein–Gauss–Bonnet model with a \(\Lambda \) -term

A D-dimensional gravitational model with a Gauss–Bonnet term and the cosmological term \(\Lambda \) is considered. By assuming diagonal cosmological metrics, we find, for a certain fine-tuned \(\Lambda \), a class of solutions with exponential time dependence of two scale factors, governed by two Hubble-like parameters \(H >0\) and \(h 3\) and \(l > 1\), respectively, with \((m,l) ...

Dilatonic dyon-like black hole solutions in the model with two Abelian gauge fields

Dilatonic black hole dyon-like solutions in the gravitational 4d model with a scalar field, two 2-forms, two dilatonic coupling constants \(\lambda _i \ne 0\), \(i =1,2\), obeying \(\lambda _1 \ne - \lambda _2\) and the sign parameter \(\varepsilon = \pm 1\) for scalar field kinetic term are considered. Here \(\varepsilon = - 1\) corresponds to a ghost scalar field. These solutions ...

On stability of exponential cosmological solutions with non-static volume factor in the Einstein–Gauss–Bonnet model

A \((n+1)\)-dimensional gravitational model with Gauss–Bonnet term and a cosmological constant term is considered. When ansatz with diagonal cosmological metrics is adopted, the solutions with an exponential dependence of the scale factors, \(a_i \sim \exp { ( v^i t) }\), \(i =1, \dots , n \), are analyzed for \(n > 3\). We study the stability of the solutions with non-static ...

Quantum billiards with branes on product of Einstein spaces

We consider a gravitational model in dimension D with several forms, l scalar fields and a \(\Lambda \)-term. We study cosmological-type block-diagonal metrics defined on a product of an 1-dimensional interval and n oriented Einstein spaces. As an electromagnetic composite brane ansatz is adopted and certain restrictions on the branes are imposed the conformally covariant ...

On exponential cosmological type solutions in the model with Gauss–Bonnet term and variation of gravitational constant

A \(D\)-dimensional gravitational model with Gauss–Bonnet term is considered. When an ansatz with diagonal cosmological type metrics is adopted, we find solutions with an exponential dependence of the scale factors (with respect to a “synchronous-like” variable) which describe an exponential expansion of “our” 3-dimensional factor space and obey the observational constraints on the ...

Quantum billiards in multidimensional models with branes

A gravitational \(D\)-dimensional model with \(l\) scalar fields and several forms is considered. When a cosmological-type diagonal metric is chosen, an electromagnetic composite brane ansatz is adopted and certain restrictions on the branes are imposed; the conformally covariant Wheeler–DeWitt (WDW) equation for the model is studied. Under certain restrictions asymptotic solutions ...