Chennai Mathematical Institute

Lecture Series


Nobel Week at CMI

Prof. Gerardus 't Hooft (Winner of the 1999 Nobel Prize in Physics), Professor of Theoretical Physics, Utrecht University, The Netherlands, will be in residence at the Chennai Mathematical Institute from November 16 to 22, 2009. During this period, a number of activities will be held as per the following schedule. All interested parties are welcome to attend.

Prof. 't Hooft's visit is sponsored by the Academic Alliance between CMI and Tata Consultancy Services.

  • DAY 1: Monday, November 16, 2009
    Activity: Discussions (3-5.00 PM) (Tentative)

  • DAY 2: Tuesday, November 17, 2009

    • Activity 1: Research Seminar

      Time: 11.00 am - 12.30 pm
      Venue: CMI Seminar Hall
      Title: Crystalline gravity

      Abstract:

      Matter interacting classically with gravity in 3+1 dimensions usually gives rise to a continuum of degrees of freedom, so that, in any attempt to quantize the theory, ultraviolet divergences are nearly inevitable. Here, we investigate a theory that only displays a finite number of degrees of freedom in compact sections of space-time. In finite domains, one has only exact, analytic solutions. This is achieved by limiting ourselves to straight pieces of string, surrounded by locally flat sections of space-time. Next, we suggest replacing in the string holonomy group, the Lorentz group by a discrete subgroup, which turns space-time into a 4-dimensional crystal with defects.

    • Activity 2: "Tete-e-tete with a Nobel Laureate"
      (An Interactive Session with School Students - Strictly by Invitation)

      Time: 4 PM - 5.30 PM
      Venue: CMI Seminar Hall

  • DAY 3: Wednesday, November 18, 2009

    • Activity 1: Research Seminar

      Time: 11.00 AM - 12.30 PM
      Venue: CMI Seminar Hall
      Title: Deterministic quantum mechanics

      Abstract:

      Investigating a class of models that is familiar in studies of cellular automata, we find that quantum operators can be employed to describe their long distance behavior. These operators span a Hilbert space that appears to turn such a model into a genuine quantum field theory, obeying the usual conditions of locality in terms of its quantum commutators. Entangled states can be constructed exactly as in quantum theories. This raises the question whether such models allow Bell's inequalities to be violated. Being a local, deterministic theory, one would argue that this is impossible, but since at large distance scales the model does not seem to differ from real quantum field theories, there is reason to wonder why it should not allow entangled states. The standard arguments concerning Bell's inequalities are re-examined in this light.

    • Activity 2: Public Lecture

      Time: 6.00 PM - 7.30 PM
      Venue: Triple Helix Auditorium, CLRI
      Title: Mini Black Holes and Quantum Physics
      Abstract:

      The Standard Model of Elementary Particles emerged empirically as an extremely efficient way to describe all particles and forces that have been detected experimentally thus far. However, in these experiments, the gravitational force was far too weak to be taken into account. In our attempts to include gravity, we encounter the difficulty that black holes might form. Their very nature causes unforeseen difficulties when we try to formulate a theory consistent with quantum mechanics. Is there information loss? Is quantum mechanics still valid? Will general relativity be an exact symmetry for very energetic particles? Something very peculiar seems to happen with clocks and rulers inside black holes.

  • DAY 4: Thursday, November 19, 2009

    • Activity: Research Seminar

      Time: 3.30 PM
      Venue: IMSc
      Title: Instantons and scalar mesons

      Abstract:

      Instantons in QCD are known to break chiral U(N) x U(N) down to SU(N) x SU(N) x U(1), where N is the number of flavors. This directly affects the mass spectrum of the pseudoscalar mesons, since these act as the Goldstone bosons of this symmetry. It is not so well known, however, that instantons also have noticeable effects in the mass spectrum of the scalar mesons. For a long time, there has been confusion as to whether the excited states of scalar mesons are biquark or tetraquark states. Knowing the interactions due to instantons, one can clarify the situation.

  • DAY 5: Friday, November 20, 2009

    • Activity: Research Seminar

      Time: 11.00 AM - 12.30 PM
      Venue: CMI Seminar Hall
      Title: Quantum gravity without space-time singularities or horizons

      Abstract:

      In an attempt to re-establish space-time as an essential frame for formulating quantum gravity - rather than an "emergent" one - we find that exact invariance under scale transformations is an essential new ingredient for such a theory. Use is made of the principle of "black hole complementarity", the notion that observers entering a black hole describe its dynamics in a way that appears to be fundamentally different from the description by an outside observer. These differences can be boiled down to conformal transformations. If we add these to our set of symmetry transformations, black holes, space-time singularities, and horizons disappear.




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