82 citations · 287 across the 12 of their papers we have counts for
13 papers
Taming the infrared in de Sitter space: autonomous equations, stochastic approach, and Borel resummation
Alexander Kamenshchik, Polina Petriakova, Tereza Vardanyan
We investigate the divergent perturbative series of correlation functions for a massless, self-interacting scalar field in de Sitter space. First, we use our previously proposed me…
Massive scalar field in de Sitter spacetime: a two-loop calculation and a comparison with the stochastic approach
Alexander Yu. Kamenshchik, Alexei A. Starobinsky, Tereza Vardanyan
We examine long-wavelength correlation functions of massive scalar fields in de Sitter spacetime. For the theory with a quartic self-interaction, the two-point function is calculat…
Time and Evolution in Quantum and Classical Cosmology
Alexander Yu. Kamenshchik, Jeinny Nallely Perez Rodriguez, Tereza Vardanyan
We analyze the issue of dynamical evolution and time in quantum cosmology. We emphasize the problem of choice of phase space variables that can play the role of a time parameter in…
Renormalization group inspired autonomous equations for secular effects in de Sitter space
Alexander Yu. Kamenshchik, Tereza Vardanyan
We develop a method for treating a series of secularly growing terms obtained from quantum perturbative calculations: autonomous first-order differential equations are constructed…
Spatial Kasner solution and an infinite slab with constant energy density
Alexander Yu. Kamenshchik, Tereza Vardanyan
We study the solutions of the Einstein equations in the presence of a thick infinite slab with constant energy density. When there is an isotropy in the plane of the slab, we find…
Duality between static spherically or hyperbolically symmetric solutions and cosmological solutions in scalar-tensor gravity
Alexander Yu. Kamenshchik, Ekaterina O. Pozdeeva, Alexei A. Starobinsky +4
We study static spherically and hyperbolically symmetric solutions of the Einstein equations in the presence of a conformally coupled scalar field and compare them with those in th…
Non-Canonical Inflation and Primordial Black Holes Production
Alexander Y. Kamenshchik, Alessandro Tronconi, Tereza Vardanyan +1
We study a mechanism for the amplification of the inflationary scalar perturbation when the inflaton field action is non-canonical, i.e. the inflaton kinetic term has a non-standar…
Exact solutions of the Einstein equations for an infinite slab with a constant energy density
Alexander Yu. Kamenshchik, Tereza Vardanyan
We find exact static solutions of the Einstein equations in the spacetime with plane symmetry, where an infinite slab with finite thickness and homogeneous energy (mass) density is…
Time in quantum theory, the Wheeler-DeWitt equation and the Born-Oppenheimer approximation
Alexander Yu. Kamenshchik, Alessandro Tronconi, Tereza Vardanyan +1
We compare two different approaches to the treatment of the Wheeler-DeWitt equation and the introduction of time in quantum cosmology. One approach is based on the gauge-fixing pro…
Quantum Gravity, Time, Bounces and Matter
A. Y. Kamenshchik, A. Tronconi, T. Vardanyan +1
In the context of Quantum Cosmology and the Wheeler-DeWitt equation we investigate the possible effects of a non semiclassical wave-function of the universe on the evolution of the…
Comment about the vanishing of the vacuum energy in the Wess-Zumino model
Andrei O. Barvinsky, Alexander Yu. Kamenshchik, Tereza Vardanyan
We check the cancellation of the vacuum energy in the Wess-Zumino model at the two-loop order in the component field formalisms with and without auxiliary fields. We show that in b…
Pauli-Zeldovich cancellation of the vacuum energy divergences, auxiliary fields and supersymmetry
A. Yu. Kamenshchik, A. A. Starobinsky, A. Tronconi +2
We have considered the Pauli-Zeldovich mechanism for the cancellation of the ultraviolet divergences in vacuum energy. This mechanism arises because bosons and fermions give contri…
Casimir effect for parallel plates in de Sitter spacetime
E. Elizalde, A. A. Saharian, T. A. Vardanyan
The Wightman function and the vacuum expectation values of the field squared and of the energy-momentum tensor are obtained, for a massive scalar field with an arbitrary curvature…