Dmitry Podolsky has got his PhD from Landau Institute for Theoretical Physics. He currently works as postdoc at Case Western Reserve University. He is also one of the editors of NEQNET.

60. Daughter

Dear all I am very sorry for being away for so long time, but maybe the following explanation will help you understand why I was so busy with other things: On September 24 my wife Anna have delivered an extremely beautiful, small but fit baby girl. We decided to call her Agata on the same [...]

59. Eye on Arxiv: Quantum corrections to eta/s

I decided to turn the de Sitter discussion off for a moment, it would be more appropriate to return to it after the paper is ready anyway Hopefully, it will not take too much time for you to see it in ArXives. Today I want instead to briefly discuss the paper “Quantum corrections to eta/s” [...]

58. Stability of de Sitter space: dS as a perfect interferometer

Let us now show that QFT of a massive scalar field in de Sitter space features instabilities if the number of dimensions is odd. The expression for the two-point function found in the previous post will be of no help, so we will have to switch to the language of Bogolyuov coefficients and modes. In [...]

57. Stability of de Sitter space: statement of the problem 1

Ok, friends, I feel that the time has come to let you know about things I am currently involved in – namely, understanding of intrinsic stability of the de Sitter space. The reason why I am so much excited about the subject that I was quiet for the whole week (or so?) is this paper by Alexander [...]

56. Birthday

Today, celebrating my birthday, I realized that it I may have well reached the middle of my life – considering that the average length of a russian man’s life today does not impress much (age VEV < 70, I believe). Probably, the latter has something to do with 1) our genes (that I cannot fix [...]

55. Eternal inflation: stochastic approach 3 (Inflationary perturbations 7)

Last time we have found that dynamics of the inflaton field (more precisely, its expectation value w.r.t. to the distribution among different Hubble patches) is determined by the Langevin equation. As we know, there are two descriptions of the Brownian motion: in terms of the Langevin equation and in terms of the Fokker-Planck equation describing [...]

54. Eternal inflation: stochastic approach 2 (Inflationary perturbations 7)

In the previous post we have started to discuss the regime of eternal inflation realized when classical displacement of the inflaton field becomes comparable with the average amplitude of fluctuations generated at super-Hubble scale. The latter in practice means that the gravitational perturbations become of the same order as the background. How to treat theory [...]

53. Eternal inflation: stochastic approach 1 (Inflationary perturbations 7)

In this post I start to discuss physics of eternal inflation – regime where superhorizon cosmological perturbations become of the order 1.

52. Introduction to non-gaussianities (Inflationary perturbations 6)

This post is the next in the series devoted to study of inflationary perturbations. I discuss the physics of non-gaussianities at the introductionary level, explain the shape of non-gaussianities and estimate their order for a single-field inflationary model.

51. Planck 2008: day 4 – Soft wall AdS/QCD

I discuss the soft wall AdS/QCD model introduced by Batell&Gherghetta, where AdS gravity and dilaton behavior providing soft wall cutoff is introduced self-consistently.