Martine Schut

# FotU symposium recap: Shahn Majid, Joe Silk and Robbert Dijkgraaf (afternoon program)

Watch back the talks by Shahn Majid, Joe Silk and Robbert Dijkgraaf below:

__14:00-14:45: Shahn Majid__

**Title**: Fuzzy black holes and quantum gravity on finite spacetimes

**Abstract:** We use the new formalism of quantum Riemannian geometry to construct quantum gravity in the case where the Universe is finite, such as four points forming a square or with `coordinate algebra’ the space of 2 x 2 matrices, as examples respectively of discrete or fuzzy noncommutative spacetimes. We then turn to fuzzy cosmological and black hole models where the 2-sphere at each fixed time and radius is replaced by a fuzzy sphere, explaining how a small amount of noncommutativity has drastic consequences. These are mostly drawn from my recent papers with Lira-Torres and Argota-Quiroz. The formalism itself starts with a bimodule of differential 1-forms over the coordinate algebra, which could be noncommutative, a metric as a noncommutative rank (0,2) tensor, and a quantum Levi-Civita connection as in my recent monograph with Edwin Beggs. If time, we will mention other potential applications including adapting Connes' approach to the Standard Model of particle physics.

__15:00-15:45: Joe Silk__

**Title**: Cosmology from the Moon: two concepts to explore

**Abstract: **I will review the prospects for future progress in cosmology. I will give examples of two futuristic experiments. One can obtain the dark ages signature via low frequency radio astronomy on the lunar far side. Attainable angular resolution potentially opens up huge numbers of modes to provide a new and robust probe of inflationary cosmology. A second direction involves a far infrared telescope to search for the elusive deviations from the blackbody spectrum of the cosmic microwave background. This could provide an unprecedented probe of the Universe in its first hundred thousand years. Both concepts could be implemented in future decades via lunar observatories.

__16:00-16:45: Robbert Dijkgraaf__

**Title**: The Future of fundamental physics

**Abstract: **What are the prospects and roles of theory and mathematics in understanding the fundamental structures of nature?