Seminar: "Big Bang, Cosmological Constant, and Quantum Gravity: Wonders of the Century" Dr. Gianluca Calcagni

Speaker:

Dr. Gianluca Calcagni

Instituto de Estructura de la Materia

Consejo Superior de Investigaciones Cientificas (CSIC), Spain 

Title: "Big Bang, Cosmological Constant, and Quantum Gravity: Wonders of the Century"

Abstract

Three questions have been haunting modern physics during the last decades. The first is whether singularities such as those inside black holes or the initial big bang that gave birth to the cosmos can be resolved. The second is about disclosing the real nature of the main and most mysterious component of the Universe, dubbed dark energy or cosmological constant. Neither the big bang nor the cosmological constant problem can be accommodated in general relativity or in ordinary models of particle interactions. A possibility is that they could be solved by unifying quantum physics with gravitation, but it is very difficult to formulate such a theory and to test it in experiments. Thus, the third question is about how to quantize gravity and to extract observable predictions.

After an introduction on these topics accessible to a general audience, I will overview my contributions to the field in a nontechnical way, including on the microscopic structure of quantum spacetimes, on cosmological theories beyond Einstein gravity, and the recent proposal of multifractal spacetimes, where a number of ideas in quantum gravity can be easily developed and explored by observations in colliders, of the cosmic microwave background, and of gravitational waves. Some of these approaches use, or are inspired by, multidisciplinary tools of fractal geometry, anomalous transport, complex systems, and condensed matter physics. We conclude with a perspective on future trends and research plans.

Biography

Gianluca Calcagni obtained a degree in physics at Padua University, Italy, in 2001 and his Ph.D. in physics at Parma University, Italy, on March 2, 2005. He worked at institutes in Japan, USA, and the EU, including Penn State University, the University of Sussex, and the Max Planck Institute for Gravitational Physics. He was the recipient of several fellowships and grants, including a JSPS and a Marie-Curie Intra-European fellowship. Since 2012, he has a Ramón y Cajal position at the Institute for Matter Structure of the Spanish National Research Council (CSIC), in Madrid.

Calcagni’s research areas include cosmologies beyond the standard model, quantum gravity, string theory, and multifractal spacetimes (about which he is writing a book). He is the author of more than 80 papers in physics since 2003, and of the book Classical and Quantum Cosmology just published by Springer. The big bang, the cosmological constant, and the quantum gravity problems, three of the greatest puzzles in modern theoretical physics, are his central interests. Currently, he is also obtaining a degree in psychology and working on mathematical models of animal and human behavior.