Juan Maldacena

Juan Maldacena Juan Martín Maldacena (born 10 September 1968) is an Argentine theoretical physicist and a professor at the Institute for Advanced Study, Princeton, New Jersey Princeton. He is famous for the AdS/CFT correspondence. His many honors include the Dannie Heineman Prize for Mathematical Physics Dannie Heinemann Prize (2007), Dirac Medal (ICTP) Dirac Medal of the ICTP (2008), the Pomeranchuk Prize (2012), and the Breakthrough Prize in Fundamental Physics (2012). Quotes It has been a long-standing challege for theoretical physics to construct a theory of quantum gravity. String theory is the leading candidate for a quantum theory of gravity. General Relativity has the seeds of its own destruction in it, since smooth Positive energy theorem#Initial data sets initial data can evolve into singular field configurations ... Classically this is not a problem if the singularities are hidden behind event horizons ... since this means that nothing can come out from the region containing the singularity. However, Hawking showed, under very general assumptions, that quantum mechanics implies that black holes emit particles ... In his approximation this radiation is exactly thermal and contains no information about the state of the black hole. This leads to the Black hole information paradox problem of “information loss”, since particles can fall in carrying information but what comes out is featureless thermal radiation ... Hawking argued that this would lead to non-unitary evolution, so that one of the basic principles of quantum mechanics would have to be modified. Black Holes in String Theory (PhD Thesis at Princeton University) arXiv:hep-th/9607235v2 1996 https://arxiv.org/abs/hep-th/9607235 In most situations, the contradictory requirements of quantum mechanics and general relativity are not a problem, because either the quantum effects or the gravitational effects are so small that they can be neglected or dealt with by approximations. When the Curved spacetime curvature of spacetime is very large, however, the quantum aspects of gravity become significant. It takes a very large mass or a great concentration of mass to produce much spacetime curvature. Even the curvature produced near the sun is exceedingly small compared with the amount needed for quantum gravity effects to become apparent.Though these effects are completely negligible now, they were very important in the beginning of the big bang, which is why a quantum theory of gravity is needed to describe how the big bang started. Such a theory is also important for understanding what happens at the center of black holes, because matter there is crushed into a region of extremely high curvature. Because gravity involves spacetime curvature, a quantum gravity theory will also be a theory of quantum spacetime ... November 2005 The illusion of gravity Scientific American 293 5 56–63 https://www.ias.edu/sites/default/files/sns/sciam-maldacena-3a.pdf (quote from pp. 58–59) These Isometry isometries of Anti-de Sitter space AdS are very powerful. Let us recall the situation in flat space. If we have a massive Geodesics in general relativity geodesic in flat space then we can always boost to a Inertial frame of reference frame where the particle is at rest. In AdS it is the same: if we consider the oscillating trajectory of a massive particle then we can "boost" to a frame where the particle is at rest. Thus, the moving particle does not know that is moving and, despite appearances, there is no "center" in AdS. The Hamiltonian is part of the symmetry group (as in the Poincaré group) and there are several choices of Hamiltonian. Once we choose a Hamiltonian ... then we have chosen a "center" and a notion of the Zero-point energy lowest energy state, in which a particle sits at this "center." Cambridge University Press 9781107013452 2012 Chapter. The gauge/gravity duality by Juan Maldacena Black holes in higher dimensions 325–347 https://books.google.com/books?id=12eGVHojt2UC&pg=PA327 (422 pages; quote from p. 327; edited by Gary Horowitz Gary T. Horowitz) Interestingly, both quantum entanglement and wormholes date back to two articles written by Albert Einstein and his collaborators in 1935. On the surface, the papers seem to deal with very different phenomena, and Einstein probably never suspected that there could be a connection between them. In fact, entanglement was a property of quantum mechanics that greatly bothered the German physicist, who called it Action at a distance#"Spooky action at a distance" “spooky action at a distance.” How ironic that it now may offer a Wormhole#Einstein–Rosen bridges bridge to extend his relativity theory to the quantum realm. November 2016 Black holes, wormholes and the secrets of quantum spacetime Scientific American 315 5 26–31 https://www.ias.edu/sites/default/files/sns/files/FinalScienticAmericanArticle.pdf ... spacetime as a concept leads to some Singularity (mathematics) singularities … where the equations fail. This happens in the interiors of the black holes when spacetime somehow collapses ... And, also, most importantly it happened in the beginning of the Big Bang. Juan Maldacena: 2017 Breakthrough Prize Laureate Interviews Breakthrough, YouTube February 20, 2018 https://www.youtube.com/watch?v=LBmdk4hp1Co&t=19s (quote at 0:19 of 4:18; 2017 Breakthrough Prize held on December 4, 2016 at Hangar One (Moffett Federal Airfield) NASA’s Hangar One in Mountain View, California) External links Juan M. Maldacena Institute for Advanced Study https://www.ias.edu/sns/malda (with several important links) Category:1968 births Category:Living people Category:Harvard University faculty Category:MacArthur Fellows Category:Members of the United States National Academy of Sciences Category:People from Buenos Aires Category:Physicists from Argentina Category:Princeton University alumni