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Calendar of Physics Talks Vienna
| The semiclassical limit of the Dirac equation“ |
| Speaker: | Jakob Möller (CMLS, École Polytechnique, Palaiseau) |
| Abstract: | The Dirac equation was discovered by Paul Dirac in 1928 in order to find a first-order in time Lorentz-invariant Schrödinger equation for particles with half-integer spin. He discovered that the scalar wave function of the Schrödinger equation had to be replaced by a 4-component vector-valued wave function, which includes the two spin states of a charged fermion and predicted its antiparticle. The vector-valued nature implies that the Dirac operator is matrix-valued. In order to treat the semiclassical limit we transform the Dirac equation into the Wigner equation for the matrix-valued Wigner transform, which converges to the positive definite Wigner matrix measure. The latter obeys a matrix-valued Liouville equation where the oscillating part of the Wigner equation converges to a Lagrange multiplier that maintains the constraint that the Wigner matrix commutes with the Weyl symbol of th |
| Date: | Wed, 04.03.2026 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Seminar Room A, Waehringer Str. 17, 1090 Wien, 2nd floor |
| Contact: | D. Fajman |
| From Matrix Models to Gaussian Molecules and the Einstein-Hilbert Action |
| Speaker: | Manfred Herbst |
| Abstract: | A matrix model on a D-dimensional Riemannian manifold is introduced, whose free energy is related to the physics of Gaussian molecules and shown to result in the Einstein-Hilbert action with cosmological constant. The gravitational and the cosmological constants are both formally determined to all orders in the string perturbation expansion and expressed in terms of graph combinatorics. |
| Date: | Thu, 05.03.2026 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | TU Wien, Wiedner Hauptstrasse 8-10, seminar room 10th floor (yellow tower) |
| Contact: | Anton Rebhan, Ankit Aggarwal |
| Speaker: | Lincoln Carr (Colorado School of Mines) |
| Abstract: | folgt |
| Date: | Fri, 06.03.2026 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Helmut Rauch Hörsaal ATI |
| Contact: | Nadine Hilmar |
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