Curing singularities in cosmological evolution of F(R) gravity (2009)
Appleby, Stephen, Battye, Richard, Starobinsky, Alexei
We study F(R) modified gravity models that are capable of driving the accelerating epoch of the Universe at the present space-time curvature whilst not destroying the standard Big Bang and...
Signatures of a Graviton Mass in the Cosmic Microwave Background (2009)
Dubovsky, Sergei, Flauger, Raphael, Starobinsky, Alexei, Tkachev, Igor
There exist consistent low energy effective field theories describing gravity in the Higgs phase that allow the coexistence of massive gravitons and the conventional 1/r potential of gravity. In an...
Reconstructing Dark Energy (2006)
Sahni, Varun, Starobinsky, Alexei
This review summarizes recent attempts to reconstruct the expansion history of the Universe and to probe the nature of dark energy. Reconstruction methods can be broadly classified into parametric...
Stability properties of some perfect fluid cosmological models (2005)
Gorini, Vittorio, Kamenshchik, Alexander, Moschella, Ugo, Pasquier, Vincent, Starobinsky, Alexei
Flat FRW perfect fluid cosmologies can be reproduced as particular solutions of suitable field theoretical models. Here we investigate the stability of perfect fluid model trajectories with respect...
Caustics in Tachyon Matter and Other Born-Infeld Scalars (2002)
Felder, Gary, Kofman, Lev, Starobinsky, Alexei
We consider scalar Born-Infeld type theories with arbitrary potentials V(T) of a scalar field T. We find that for models with runaway potentials V(T) the generic inhomogeneous solutions after a short...
Prospects and Problems of Tachyon Matter Cosmology (2002)
Frolov, Andrei, Kofman, Lev, Starobinsky, Alexei
We consider the evolution of FRW cosmological models and linear perturbations of tachyon matter rolling towards a minimum of its potential. The tachyon coupled to gravity is described by an effective...
The Case for a Positive Cosmological Lambda-term (1999)
Sahni, Varun, Starobinsky, Alexei
Recent observations of Type 1a supernovae indicating an accelerating universe have once more drawn attention to the possible existence, at the present epoch, of a small positive Lambda-term...
Structure of Resonance in Preheating after Inflation (1997)
Greene, Patrick, Kofman, Lev, Linde, Andrei, Starobinsky, Alexei
We consider preheating in the theory $1/4 \lambda \phi^4 + 1/2 g^2\phi^2\chi^2 $, where the classical oscillating inflaton field $\phi$ decays into $\chi$-particles and $\phi$-particles. The...
Towards the Theory of Reheating After Inflation (1997)
Kofman, Lev, Linde, Andrei, Starobinsky, Alexei
Reheating after inflation occurs due to particle production by the oscillating inflaton field. In this paper we describe the perturbative approach to reheating, and then concentrate on effects beyond...
Comments on "Analytic and Numerical Study of Preheating Dynamics" (1996)
Kofman, Lev, Linde, Andrei, Starobinsky, Alexei
In a recent paper Boyanovsky et al (hep-ph/9608205) studied preheating for a particular theory of the inflaton field. Although they results essentially confirm those of the original papers on...
Mixed Cold-Hot Dark Matter Model with several Massive Neutrino Types (1995)
Pogosyan, Dmitri, Starobinsky, Alexei
Mixed cold-hot dark matter cosmological models (CHDM) with $\Omega_{tot}=1$, approximately flat initial spectrum of adiabatic perturbations and 1, 2 or 3 types of massive neutrinos are compared and...
Mixed Cold-Hot Dark Matter Model with Falling and Quasi-Flat Initial Perturbation Spectra (1994)
Pogosyan, Dmitri, Starobinsky, Alexei
The mixed cold-hot dark matter cosmological model (CHDM) with $\Omega_{tot}=1$ and a falling power-law initial spectrum of Gaussian adiabatic perturbations ($n>1$) is tested using recent...
Reheating after Inflation (1994)
Kofman, Lev, Linde, Andrei, Starobinsky, Alexei
The theory of reheating of the Universe after inflation is developed. The transition from inflation to the hot Universe turns out to be strongly model-dependent and typically consists of several...