University of Tartu physicists organise a teleconference on teleparallel gravity

Computer simulation of two inspiralling black holes. Author: Simulating eXtreme Spacetimes Lensing

On 15–19 June, the University of Tartu Institute of Physics will host an international online conference on teleparallel theories of gravity, where about 100 theoretical physicists and mathematicians from all continents have registered their interest to attend.

In mathematical terms Einstein’s 1915 theory of general relativity describes the force of gravity by spacetime curvature. This explains many astronomical phenomena, and has recently received remarkable confirmation by the observations of gravitational waves as well as the black hole image. Yet the unresolved puzzles of dark matter and dark energy invite the researchers to think beyond general relativity. In fact, Einstein himself in his later years played with the alternative geometric notions of torsion and nonmetricity to model gravity. Such theories where the spacetime has no curvature are called “teleparallel” in the mathematical language.

These early ideas did not receive too much attention, as general relativity seemed to work well, but were later picked up and developed further by other researchers. “Currently we know several alternative formulations leading to the equivalent classical dynamics. The question arises whether the geometry of spacetime can be decided by experiments, or whether it is merely a matter of convention,” Tomi Koivisto, Senior Research Fellow of Theoretical Physics at the University of Tartu and one of the conference organisers, explained the crux of the problem.

The conference is already the fourth consecutive international scientific meeting dedicated to the geometric foundations of gravity, organised by the University of Tartu Institute of Physics as a part of the activities of the Centre of Excellence The Dark Side of the Universe. “This conference was initially planned as a relatively small and specialised workshop to discuss some recent results and ponder the open problems, but as the travel restrictions forced the event to go online, the participation numbers tripled,” said Laur Järv, Senior Research Fellow of Theoretical Physics and Assistant Director of the institute.

The conference talks and discussions are scheduled to take place in a narrow time frame from 12 to 18, to better accommodate participants from the distant time zones of Asia and America. The welcome event is replaced by a TeleQuiz, and instead of the conference excursion, the participants are invited to visit the virtual exhibition hall of the University of Tartu Museum.

On Tuesday, 16 June at 18, Professor Emmanuel Saridakis of the National Technical University of Athens and Hefei University of Technology, and Lead Researcher at the National Observatory of Athens, delivers a popular lecture describing the most recent insights and discoveries from the cosmos, “Black holes and gravitational waves: a new window to look at the universe”. The lecture is held in English and is accessible online for free.

More details are available on the conference webpage.

Additional information: Laur Järv, Senior Research Fellow, Assistant Director of Institute of Physics, University of Tartu, +372 5341 6324, laur.jarv [ät]