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. **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

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 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 ...

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 ...

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 ...

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 ...

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 ...