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.

20. More on KS throat cloaking…

Was thinking about recent paper by Alex Buchel and Lev Kofman… and found that I have a couple of naive questions: 1) cloaking is 5 dim picture (well, 10-dim) – i.e., throat for bulk CY observer is seen as AdS black hole. What is the picture for 4dim observer, the one who lives on the [...]

19. Disorder on the landscape: non-technical intro

Today I will kindly allow myself a bit of selfpromotion As I said yesterday, our paper “Disorder on the landscape” is finally out (by the way, Lubos Motl already has a very nice post about it on his blog). So, what is the paper about? 1. Cosmological constant problem There exists a serious problem in [...]

18. Eye on ArXiv: 15 Apr 2008 – Transplanckian physics, brane cosmology and holographic mesons

Sorry for being quiet for so long. The reason is we were finising a paper, asked for comments and got a lot of them. The paper is finally submitted to appear on ArXiv in tomorrow’s listings. The title is “Disorder on the landscape”, and the abstract will be available tonight Helsinki time (and tomorrow for [...]

17. Beginning inflation: problem of initial conditions in cosmology (Inflationary perturbations 4)

This is the next post in the series based on my lectures on inflationary perturbations and large scale structure given at the University of Helsinki. Today we will finally start to discuss the physics of inflation and will focus on known problems of Hot Big Bang Cosmology.

16. Eye on ArXiv: 10 Apr 2008 – NG in ekpyrotic models, quantum noise as entanglement meter

Ekpyrotic scenario predicts much higher level of primordial non-gaussianity than single field inflationary scenarios.

15. Anderson localization. Just crossed my mind…

I personally consider Anderson localization as one of the most prominent dynamic vacuum selection principles on the string theory landscape. Let me remind you the main idea behind it. In condensed matter theory, Anderson localization was first discovered as a phenomenon of electron wave function localization inside a semiconductor when disorder (for example, impurities or [...]

14. Eye on ArXiv: 8 Apr 2008 – Unifying inflation, dark matter and dark energy?

1. Andrew R. Liddle, Cedric Pahud, L. Arturo Urena-Lopez, “Triple unification of inflation, dark matter, and dark energy using a single field”. The title says for itself; the paper is a development of older Andrew’s idea, which is the following. Suppose that inflation is driven by a scalar field with the potential . Inflaton slowly [...]

13. Eye on ArXiv: 7 Apr 2008 – Gravity cutoff in theories with large descrete symmetries

Gia Dvali, Michele Redi, Sergey Sibiryakov, Arkady Vainshtein, “Gravity Cutoff in Theories with Large Discrete Symmetries” It is a development of one year old extremely elegant Dvali’s idea that the possible maximal number of species is bounded by the gravitational physics. Let me demonstrate what they have found. One takes a large black hole and [...]

12. Eye on ArXiv: 4 Apr 2008 – KS throat cloaking, non-gaussianity and Mathur’s fuzzballs

1. Alex Buchel, Lev Kofman “Black Universe epoch in string cosmology” Alex and Lev write about multithroat scenario in string cosmology. As we remember, typically one needs more than a single throat in KKLMMT-type scenarios because the single throat setup does not solve the hierarchy problem (the energy scale of the throat is inflationary, while [...]

11. Introduction into perturbation theory in general relativity 4 (Inflationary perturbations 3)

Today I am going to discuss equations driving the dynamics of cosmological perturbations. As you remember, we are considering now gravitational perturbations in general relativity, so these equations are nothing else but Einstein equations in where one keeps only first order terms w.r.t. perturbations of the metric tensor. I will consider cosmological perturbations in longitudinal [...]