GÖDEL-TYPE UNIVERSES IN f(T) GRAVITY
نویسندگان
چکیده
منابع مشابه
Gödel-type Universes in String-inspired Charged Gravity
We consider a string-inspired, gravitational theory of scalar and electromagnetic fields and we investigate the existence of axially-symmetric, Gödel-type cosmological solutions. The neutral case is studied first and an “extreme” Gödel-type rotating solution, that respects the causality, is determined. The charged case is considered next and two new configurations for the, minimally-coupled to ...
متن کاملBlack holes in Gödel universes and pp waves.
We find exact solutions for rotating and nonrotating neutral black holes in the Gödel universe of five-dimensional minimal supergravity theory. We also describe the embedding of this solution in M-theory. After dimensional reduction and T-duality, we obtain a supergravity solution corresponding to placing a black string in a pp-wave background.
متن کاملLattice Universes in 2+1-dimensional gravity
Lattice universes are spatially closed space-times of spherical topology in the large, containing masses or black holes arranged in the symmetry of a regular polygon or polytope. Exact solutions for such spacetimes are found in 2+1 dimensions for Einstein gravity with a non-positive cosmological constant. By means of a mapping that preserves the essential nature of geodesics we establish analog...
متن کاملBouncing Universes in String-inspired Gravity
We consider the effects on cosmology of higher-derivative modifications of (effective) gravity that make it asymptotically free without introducing ghosts. The weakening of gravity at short distances allows pressure to prevent the singularity, producing a solution with contraction preceding expansion.
متن کاملBaby Universes in 2d Quantum Gravity
We investigate the fractal structure of 2d quantum gravity, both for pure gravity and for gravity coupled to multiple gaussian fields and for gravity coupled to Ising spins. The roughness of the surfaces is described in terms of baby universes and using numerical simulations we measure their distribution which is related to the string susceptibility exponent γstring.
متن کاملذخیره 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: International Journal of Modern Physics D
سال: 2012
ISSN: 0218-2718,1793-6594
DOI: 10.1142/s0218271812500745