Cracking gravity in Tartu with a Spanish grant

In January 2022 the gravity theory group at the Laboratory of Theoretical Physics, Institute of Physics was joined by Francisco José Maldonado Torralba from Spain, who came to Tartu with the grant awarded by the Fundación Ramón Areces. He graduated with PhD from the Complutense University of Madrid, and has previously worked as a postdoc in Groningen, Cape Town, and Oslo.

Before his talk at the theoretical physics seminar, Francisco shared bits of his research and first impressions in Tartu.

What are the main objectives of your project?

I am interested in modifications of Einstein’s theory of general relativity, and how this leads to new phenomenology that can potentially explain the current problems in gravitation and cosmology. As in every scientific discipline, it is always exciting to find phenomena that we cannot explain with our current models of nature. When this happens, we can consider two lines of thought. Either there is something that we have not directly observed yet but which is indirectly causing the strange behavior. In the case of gravity the latter is dubbed dark matter and dark energy. The alternatiive view is that the current theory must be incomplete. This second approach seems more appealing to me, which leads to the research I am performing now. My objective is to explain the current problems in gravity with a certain kind of gravitational theories, known as gauge modifications of gravity, without recurring to dark matter or dark energy. Moreover, I would like to propose experimental signatures that differentiate our models from the usual ones.

Why did you choose Tartu to carry out the project here?

I strongly believe that the Laboratory of Theoretical Physics of the University of Tartu is one most prolific environments to work on gauge theories of gravity. The department is composed of a very strong core of established researchers in this area such as Dr. Laur Järv, Dr. Tomi Koivisto, and Dr. Manuel Hohmann. Also, there are several postdoctoral fellows exploring different aspects of these theories, as well as continuous visitors and seminar speakers. Moreover, I knew many of the members of the laboratory before coming here, which makes the beginning of the postdoc a lot easier. This makes it a perfect place to work as a group, which always leads to more interesting ideas.

What are your first impressions from Tartu?

I am really enjoying it so far. I think it is a really nice and beautiful city, and the enviroment at the university is amazing. It has been very easy to adapt because people have been very friendly and helpful. Also, the fact that in the city you find people from all around the world, makes living here a very enriching experience. Although I hope eventually I won't fall on the ice so much :)