Journal club
142. Chaotic inflation on the landscape?
By a chance, do you remember the paper by Nemanja Kaloper and Lorenzo Sorbo that we have recently discussed? There, the authors were modeling quintessence by axion-like fields that dynamically mix with 4-form fields. The mixing introduced mass terms for the axions approximately preserving the shift symmetry. (By the way, I was surprised to see how many people are looking for “Caloper Sorbo quintessence” in Google 
– it seems that the topic is going to become hot soon.)
Read more on 142. Chaotic inflation on the landscape?…
141. On information loss paradox, statistical and quantum mechanics
Recently, I got into the discussion of information loss paradox in spacetimes with timelike and spacelike horizons (that is, black holes, de Sitter and staff like them). Let me remind you what is the issue (see for example Susskind’s recent book for details).
Read more on 141. On information loss paradox, statistical and quantum mechanics…
140. First two weeks of December at NEQNET
Dear friends
Before I proceed to the (becoming usual already) list of posts published at NEQNET during the last two weeks, let me say a couple of words about the blog itself, which is currently the source of my pride 
Read more on 140. First two weeks of December at NEQNET…
134. Cosmic strings – simple and nice introduction into the topic
After my recent post on textures I have been asked what could a newcomer to the field read about topological defects in cosmology apart from the canonical book by Vilenkin and Shellard that I’ve recommended?
Read more on 134. Cosmic strings – simple and nice introduction into the topic…
133. Multi-Field Inflation on the Landscape
This is the guest blog post by my friend Thorsten Battefeld from Princeton. Dmitry.
Dmitry asked me to write a guest post about a recent paper written by Diana and myself on “Multi-field Inflation on the Landscape” (a followup to “Staggered Multi-Field Inflation”) where we ask a simple question: assuming that inflaton is driven by many (say of the order of 
) scalar fields, what are the observable consequences of fields decaying or stabilizing one after the other during inflation?
Read more on 133. Multi-Field Inflation on the Landscape…
131. Non-gaussianities from postinflationary universe
Mark Trodden and Alessandra Silvestri have recently released a paper about signatures of non-gaussianity from the post-inflationary early Universe.
The title of the paper is speaking for itself: one can immediately recall that CMB fluctuations can be generated from cosmic strings and other topological defects, i.e., they may be partially sourced by various phase transitions in the very early Universe. This is indeed what Mark and Alessandra consider – in particular, they focus on effects of textures.
Read more on 131. Non-gaussianities from postinflationary universe…
127. Ashtekar at Perimeter Institute
Abhay Ashtekar has recently visited the Perimeter Institute and gave a couple of talks – about loop quantum gravity of course, since he is one of the major players in the LQG field (considered to be its inventor). I think, both of the talks are worth watching (or at least scanning through his transparencies available as PDF file at PIRSA) for a person who wants to understand what LQG is about. If you do not have an intention to watch them , I shall explain you what both of them are about.
Read more on 127. Ashtekar at Perimeter Institute…
126. From quarks to strings. Migdal-Makeenko equation and AdS-CFT correspondence
Although Lubos wants to see my answer to the poll , I decided to finish my analysis of the recent Polyakov’s paper today.
Page 6. In order to justify my picture I have used intuition coming from the loop equation, while Klebanov and Maldacena appealed to the D brane picture of the gauge fielauds. Both points of view are useful but neither of them lead to the quantitative derivation of gauge/string duality.
Comment. He is talking about the Migdal-Makeenko loop equation for the expectation value of the Wilson loop 
. After Migdal’s groundbreaking proof of the fact that this equation describes a free motion of the contour 
in the large 
limit (1981, if I am not wrong (?), even before the Polyakov’s action), not much progress has been reported in this direction. The main reason is that the Migdal-Makeenko equations are formulated on the lattice, and no their continuum limit is known (it is not clear how to perform the renormalization procedure for loops).
Read more on 126. From quarks to strings. Migdal-Makeenko equation and AdS-CFT correspondence…
125. From quarks to strings. On Liouville mode, instantons and confinement in abelian theories
Alexander Polyakov have released this week a preprint about history of string theory, which is also so full of non-trivial physical ideas that I decided to list some of them in this post as well as to include my comments (or rather my ramblings )
124. Talk in Munich. Regularizing correlators of curvature perturbation
This post is hopefully the last one in the series devoted to my seminar in Munich Last time I have explained why correlation functions of the scalar field on de Sitter background should be actually infrared finite. This time, using similar trick, I will argue that the correlation functions of the curvature perturbation 
(by curvature perturbation, as usual, I mean curvature of the 3-dimensional slice) should be also infrared finite due to the effects of eternal inflation.
Read more on 124. Talk in Munich. Regularizing correlators of curvature perturbation…
123. AdS/CFT and condensed matter applications
This post is going to be, I think, somewhat controversial but… if you feel that I greatly miss some important point regarding the subject, then please feel free to explain that to me in the comments. And the subject is… ta-da-da-daam…
Read more on 123. AdS/CFT and condensed matter applications…
121. On interaction between coherent condensate and turbulent flow in two dimensions
It looks like I did not review new nice papers in ArXiv for so long time While I have no idea what is the reason for this particular fact, I tell you that the ultimate reason for similar facts was always my tremendous laziness. What could a man do with such an evil? The only sane manly way seems to constantly try to overcome your disadvantages So, let me try.
Read more on 121. On interaction between coherent condensate and turbulent flow in two dimensions…
120. Talk in Munich. Regularizing inflaton correlation functions
Let me get again back from confinement to eternal inflation , or more precisely, to the infrared behavior of correlation functions of a self-interacting massless scalar field on de Sitter background. In what follows, I will consider the case 
(a QFT in fixed dS spacetime).
Read more on 120. Talk in Munich. Regularizing inflaton correlation functions…
118. Last two weeks of November on NEQNET
Well, those two weeks were quite productive ones! – 19 posts in overall (or 20 including this one ) This counts to 1.5 posts per day (and you should take into account that I was on leave to Munich for 4 days). I hope my writing was not too boring for you
Read more on 118. Last two weeks of November on NEQNET…
117. Recent lattice QCD simulations – how good is QCD in the infrared?
A very interesting paper on lattice QCD spectroscopy by the European collaboration (DESY, Marceille, Wuppertal, Julich) is published in the recent issue of Science.The authors were able to reproduce the mass scales of light hadrons which coincide with measured ones up to 1% precision (take a look at the Table 1 in the paper). It means that a) QCD does describe the low energy physics perfectly, i.e., we don’t need corrections to the QCD Lagrangian at energies lower than the scale of 
and b) lattice QCD has reached the stage of development when all systematic error effects are under control. No more, no less.
Read more on 117. Recent lattice QCD simulations – how good is QCD in the infrared?…
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