We would like to invite you to our Fundamentals of the Universe mini-symposium, which will take place online and at the Van Swinderen Huys on Friday, 24 September 2021 at 9 AM. To receive an invitation please register to the event via this __online form__!

The program for the symposium has just been announced, find a detailed description here below:

__Program__

Moderator: Julia Even 9:00-9:25: Coffee & tea

9:25-9:30: Elisabetta Pallante (opening)

9:30-10:15: Samaya Nissanke

10:15-11:00: Tina Pollmann

11:00-11:15: Break

11:15-12:00: Stefan Teufel

12:00-14:00: Lunch and poster session

Moderator: John McKean

14:00-14:45: Shahn Majid 14:45-15:00: Break 15:00-15:45: Joe Silk 15:45-16:00: Break 16:00-16:45: Robbert Dijkgraaf 16:45-18:30: Wrap up and drinks

The posters can be found under blog posts __here__.

You can find the abstracts of the talks below:

__9:30 - 10:15: Samaya Nissanke __

**Title**: New Perspectives onto the Universe in the era of Multi-Messenger Astrophysics

**Abstract: **In the past five years, the LIGO, Virgo and KAGRA gravitational wave (GW) detectors have announced the discovery of at least fifty compact object mergers including the first two binary neutron star mergers GW170817 and GW190425 and two neutron star black hole mergers GW200105 and GW200115. The discovery of both gravitational wave and electromagnetic (EM) radiation from the first binary neutron star merger, GW170817, has opened up a new era of multi-messenger GW+EM astronomy. The EM follow-up campaign for this single event was unprecedented in terms of its scale, coordination and the resulting observational data-sets. Although only a single event, the follow-up and joint GW+EM characterization have offered us new perspectives on the Universe enabling critical insights into diverse fields from gravity, high-energy astrophysics, nuclear physics, to cosmology. In this talk, I will give an overview of the GW discovery and EM follow-up of this event and subsequent neutron star mergers, and then discuss how to place compact object mergers in their full astrophysical context using joint GW+EM measurements. I will conclude by discussing the lessons that we are learning from these neutron star binary mergers. Finally, I will provide my perspective on the remarkable opportunities and challenges that have emerged in this new observationally-driven and fast-paced field as we move from the discovery era to one of precision astrophysics in this decade.

__10:15-11:00: Tina Pollmann__

**Title:** Direct searches for Dark Matter
**Abstract: **The nature of approximately 27% of the mass-energy content of the universe, or 85% of the total mass in the universe, is currently unknown. Cosmological and astrophysical observations require this extra mass to account for the depths of gravitational potentials inferred from the velocities of astrophysical objects, the paths of light past astrophysical objects, and the structures in the cosmic microwave background. Observations consistently indicate that this extra mass cannot be the regular, or ‘baryonic’, matter we are familiar with. Assuming that this ‘dark matter’ is made from a new type of particle, the properties we can infer from astrophysical observations are that this particle is stable at timescales comparable to the age of the universe, does not interact via the strong or electro-weak forces, and is not accounted for in the standard model of particle physics. The hypothesis of dark matter as a new type of particle is currently favoured, since the existence of such a particle would explain not just astrophysical and cosmological observations, but could resolve inconsistencies in the standard model of particle physics at the same time.
A global effort to detect this hypothetical dark matter particle and to study its properties has now been ongoing for several decades. Out of several experimental approaches, this lecture will focus on direct detection of a class of hypothetical particles called WIMPs - weakly interacting massive particles - that arise from attempts to mend inconsistencies in the standard model of particle physics, and happen to have the right properties to account for the dark matter content in the universe. In a direct detection experiment, a detector on earth is built for galactic WIMPs to interact in as earth passes through our galaxy's dark matter halo. To detect interactions between this very rarely interacting type of particle and our detector’s target material, extremely sensitive detectors with unprecedented control of interfering standard-model particles are being built in deep-underground laboratories. This lecture will explain the direct detection challenges and the most important experimental techniques currently in use.

__11:15-12:00: Stefan Teufel__

**Title:** Bohmian Mechanics from a Mathematician's Perspective
**Abstract: **Bohmian mechanics is a deterministic theory for the motion of point particles, more precisely a first-order nonautonomous dynamical system. Its relevance stems from the fact that one can show, by a relatively simple statistical equilibrium analysis, that the empirical predictions of this theory agree with those of the standard quantum mechanical measurement formalism when the latter makes unambiguous statements. In my talk I will review this "derivation" of the quantum measurement formalism from Bohmian mechanics, focusing on its mathematical structure and pointing to rigorous results.

__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?

__Participants list (23 September, 10:35 AM)__

Gianni van Marion

Steven Hoekstra

Julia Even

Edwin A. Valentijn

Rob Timmermans

Jorge Becerra

Willem-Jan Vriend

Alba Kalaja

Diederik Roest

Betsey Adams

Maria Domenica Galati

Gerco Onderwater

Hugo Buddelmeijer

Bram Alferink

Leon Koopmans

Wim Brouw

Xiangcheng Chen

Arif Soylu

Manuela Vecchi

Eric J. Pap

Julian Putman

Eric Bergshoeff

Thomas Flöss

Martine Schut

Ceyda Simsek

Pratika Dayal

Holger Waalkens

Alef Sterk

Nikolay Martynchuk

Kevin van Helden

Bohdan Bidenko

Martijn Kluitenberg

Bram Brongers

Pierluigi Rinaldi

Kristof De Bruyn

Ema Dimastrogiovanni

Dijs de Neeling

Lars Knipping

Leon Koopmans

Hans Wilschut

Jelle Bor

Cormac Larkin

Bharath Chowdhary Nagam

Nicolaas P. Landsman

Di Wen

Luca Romano

Daan meerburg

Riccardo Bonetto

Roland van der Veen

Maxime Trebitsch

Paul Wesselius

Vlad-Haralambie Ispas

Mina Morshed Behbahani

John McKean

Felix Semler

Alex Lande

Nithesh Balasubramanian

Marc Verheijen

Felix Semler

Edwin van Bloois

Bart Schellenberg

Ties Fikkers

Robert Sanders

Piet van der Kruit

Johannes Lahnsteiner

Joost van Hofslot

Ludovica Benedetta Riccardi

Bharath Chowdhary Nagam

Wout Moltmaker

Jan van Neerven

Robert Sanders

Thomas B Meijknecht

Rien van de Weijgaert

Sabri BOULSNANE

Jann Aschersleben

Shubham Maheshwari

Giorgio Orlando

Elisabetta Pallante

Jonas Bremer

Panos Christakoglou

Joris van Heijningen

Emily Brookes

Christian Korthals Altes

Emma Godden

Christos Pliatskas

Daniel Boer

Maria Dziouba

Heidi de Vos

Reynier Peletier

Fabian IJpelaar

Heidi

Luis Guillermo Venegas Pineda

Piet Mulders

Gijs Wiersema

Wim Brouw

Pranav Kukreti

Jeffrey Weenink

Hyoyin Gan

Barbara Šiljeg

Joost van Hofslot

Aleksandra Kiuberis

Martino Michelotti

Boudewijn Bosch

Ruben Hendriks

Thomas Dam

Folmer Bokma

Max Wiegertjes

Arthemy Kiselev

Hildeberto Jardon Kojakhmetov

Oscar Koster

Ricardo Buring

Alex Cole

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