A christmas present for string theorists from Matthew Headrick

Today in Arxiv it hs appeared the following paper: A solution manual for Polchinski's "String Theory"

The name says it all. The abstrac dissipates any possible dude:

We present detailed solutions to 81 of the 202 problems in J. Polchinski's two-volume textbook "String Theory".

Also I find interesting the announcement of Tommaso Dorigo in his blog about an upper limit on the mass of the graviton (or at least the mass of the graviton in the context of certain Randall-Sundrum models). The bblog entry is this. Of course it will be better to wait untill the corresponding arxiv paper, but it looks certainly very interesting.

Also I have noticed that Amelio Camelia is publishing recently a few papers about nonconmutative geometry in string theory. Camelia is famouse because of the paper whre he presented the idea of double special relativity. Ultimately the idea of DSR has been flawed with many problems, but still I think that it was a brilliant proposal so I am interested in reding that new papers. But before that I am reading other things that I had pending about more well stablised topics in string theory. Anway, if the papers of Camelia are interesting Ill try to bblog about then when I would read them.