Take two random articles from this weblog:

Using the BFKL pomeron exchange in a gauge theory, one can try to calculate some scattering amplitudes in the Regge limit (high-energies, small angle). A linear approximation of this calculation breaks down for some rapidity "y" that is related to the ratio of the sizes of certain two three-dimensional momenta by a scaling law

- exp(y) = (k1 / k2)^{gamma
_{BFKL}}

- gamma
_{BFKL}= 0.409552...

Now take a completely different physical system: scalars coupled to gravity. Consider a line in the scalar configuration space of initial conditions of the scalars parameterized by a single parameter "p" such that for "p=0", the system evolves into an empty Minkowski space in the future while for large values of "p", a black hole is formed. So there must be a critical value "p0" above which the black hole is formed. How heavy the black hole will be: what is the mass "M"? It depends how closely you get to "p0". Choptuik's relation is

- M = M0 x (p-p0)^{gamma
_{BH}}

argue that it is no coincidence, using the AdS5 / CFT4 correspondence, and both of these exponents are actually equal. If true, that's a rather fascinating relation between quantum phenomena in a gauge theory living in the flat space and a complicated non-linear but classical calculation in general relativity in the context of the birth of a black hole. I actually believe that the relation could be correct even though the Choptuik exponent for five-dimensional gravity is only known - also numerically - as

- gamma = 0.408 +- 2 percent

## snail feedback (1) :

Incidentaly, you can notice the heading tells

Comments: ... To Pere Pascual, in memoriam

Prof. Pascual was one of the founders of the post-war line of theoretical physics in Spain. You may know the Quantum Mechanics book coauthored with Galindo; a translation is available in Springer (and, I have seen it sometimes, in the P2P networks). Recently Pascual become involved in the launching of a summer centre for , at the pyrenees range, where he used to pass his vacation time.

Post a Comment