# Announcements

#### Upcoming events

- Bethe-Colloquium by Alain Connes, November 27th 2014
- Bethe-Colloquium by Arthur Hebecker, January 15th 2015
- Bethe Forum on "Constructive Methods in Number Theory", March 2nd to 6th 2015
- Lecture series on "Axions" by Kiwoon Choi (Institute for Basic Science, Korea), March 9th to 13th 2015
- Bethe Forum on "Methods for lattice field theory", March 23rd to April 2nd 2015

Further information will be given as soon as they are available.

#### Bethe Colloquium by Prof. Alain Connes

A second Bethe Colloquium is scheduled for November. It will take place on November 27th (3:15 pm) in Hörsaal I:

- Alain Connes (College de France, Paris)
- Quanta of Geometry
- Hörsaal I, Physikalisches Institut

**Abstract:** In the construction of spectral manifolds in noncommutative geometry, a higher degree Heisenberg commutation relation involving the Dirac operator and the Feynman
slash of real scalar fields naturally appears and implies, by equality with the index formula, the quantization of the volume. We first show that this condition implies that the
manifold decomposes into disconnected spheres which will represent quanta of geometry. We then refine the condition by involving the real structure and two types of geometric quanta,
and show that connected manifolds with large quantized volume are then obtained as solutions. When this condition is adopted in the gravitational action it leads to the quantization
of the four volume with the cosmological constant obtained as an integration constant. Restricting the condition to a three dimensional hypersurface implies quantization of the three
volume and the possible appearance of mimetic dark matter. When restricting to a two dimensional hypersurface, under appropriate boundary conditions, this results in the quantization
of area and has many interesting applications to black hole physics.

#### Bethe Colloquium by Prof. Arthur Hebecker

Janurary's Bethe Colloquium will take place on January 15th (3:15 pm) in Hörsaal I:

- Arthur Hebecker (Heidelberg University)
- String Theory Landscape and Cosmological Inflation
- Hörsaal I, Physikalisches Institut

**Abstract:** The talk will start by motivating string theory as a theory of quantum gravity. Then the resulting 10-dimensional effective field theory and its compactification to 4
space-time dimensions will be discussed. It turns out that this leads to a very large number of possibilities - the "string theory landscape". This landscape is populated through
eternal inflation, creating the so-called multiverse. To describe our observed cosmology, eternal inflation has to be supplemented by slow-roll inflation which leaves its imprint on
the cosmological microwave background, measured e.g. by the Planck satellite. Recent progress in the string-theoretical understanding of this inflationary period of our universe will
be briefly discussed at the end.