Modified gravity theories have received increased attention lately due to combined
motivation coming from high-energy physics, cosmology, and astrophysics. Among …

We present a comprehensive study of the cosmological solutions of 6D braneworld models
with azimuthal symmetry in the extra dimensions, moduli stabilization by flux or a bulk scalar …

Three-forms can give rise to viable cosmological scenarios of inflation and dark energy with
potentially observable signatures distinct from standard single scalar field models. In this …

It has been suggested that codimension-two braneworlds might naturally explain the
vanishing of the 4D effective cosmological constant, due to the automatic relation between …

We discuss the way of solving the hierarchy problem. We show that starting at the Planck
scale, the three energy scales—inflationary, electroweak and the cosmological ones can be …

We study localization of bulk fermions on a string-like defect with the exponentially
decreasing warp factor in six dimensions with inclusion of U (1) gauge background from the …

We study a gravitational model with curvature-squared R 2 and curvature-quartic R 4
nonlinearities. The effective scalar degree of freedom ϕ (the scalaron) has a multivalued …

It is shown that the α 2-dynamo of magnetohydrodynamics, the hydrodynamic Squire
equation as well as an interpolation model of PT-symmetric quantum mechanics are closely …

We consider compactifications of six-dimensional gravity in four-dimensional Minkowski or
de Sitter space times a two-dimensional sphere, S 2. As has been pointed out recently, it is …

The Starobinsky model of inflation, consistent with Planck 2015, has a peculiar form of the
action, which contains the leading Einstein term R, the R 2 term with a huge coefficient, and …