Monday, August 22, 2005

Stanford supports Newton

The Stanford experimental group around Alan Kapitulnik has found no deviations from the Newtonian gravitational law. They have improved their limits on a new force at 20 microns - a force that they parameterize as a Yukawa force - and published a paper about it, namely hep-ph/0508204. According to the newest rumors, the Washington group will also confirm a negative result. The results so far are consistent with Newton's theory much like the new Intelligent Falling theory. ;-)

It is not hard to summarize all hep-th papers today. Raman Sundrum offers his TASI lectures on the fifth dimension. Alexander Vilenkin reviews the cosmic strings and confirms that the Hubble decision about the CSL-1 galaxies (Cosmic String Lensing?) should appear by early 2006. One abstract paper speculates about the Immirzi parameter and torsion. There is shockingly one more paper about the Immirzi parameter: a new value of it is proposed. Although many people would be happy if someone else referred to their (my) work often, I am personally very confused what all these guys want to do and why they think it's interesting; see the quasinormal story on quasinormal modes. Christian Saemann studies a certain cousin of the twistor space for three-dimensional gravity - in fact it is N=8 supergravity. Agarwal and Ferretti study integrability of spin chains; they show that a new, "higher" conserved charge in the su(2|3) sector of N=4 Yang-Mills is determined algebraically. Similar questions in a different, su(1|1) sector of the same theory is studied by Alday, Arutyunov, and Frolov in relation with the free fermions. Frey, Mazumdar, and Myers argue that stringy effects can leave imprints on the CMB radiation through inflation and reheating in multi-throat cosmologies; a new, long-string era plays role in their picture. Two Sorokas argue that they can construct a multiplet in the Minkowski space with different masses in it, marginally contradicting the Coleman-Mandula theorem. Finally, Kopper tries to make some facts about renormalization flows (in the context of the Euclidean lambda.phi^4 theory) more rigorous.

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