The intended audience of this page are specialists. You can find the version for the general public here.

Charged black holes

Einstein-Maxwell’s theory is the most fundamental description of electromagnetism and gravity, and several far-reaching results on black holes were found in this context. However, since astrophysically-relevant black holes are believed to have negligible electric charge, the theory has been mostly confined within the realm of theoretical investigation. Consequently, interacting charged black holes represent a largely unexplored territory.

I apply numerical-relativity techniques to perform simulations of such systems. I mostly focus on ultra-relativistic head-on collisions and quasi-circular inspirals. The latter are possible sources for current and future gravitational-wave detectors. In particular, I applied the conformal transverse traceless method to generate initial data for arbitrary systems of charged black holes. This formalism is implemented in a spectral code called TwoChargedPuncture.

I believe that charged black holes are a perfect laboratory where to learn about the interplay between extreme gravitational and electromagnetic fields, the understanding of which could be relevant also for other astrophysical applications. In addition to that, the mathematical framework used to describe charged black holes can be employed for a large variety of different physical systems, such as modified theories of gravity. One of my important results on the subject is the first constraint on black-hole charge from gravitational waves.

Rotating-relativistic stars

The study of neutron stars brings together several different fields ranging from astrophysics and gravitation to particle and nuclear physics. My research focuses on rotating neutron stars, the properties of which are significantly different compared to the static case. I studied stability properties of differentially rotating compact stars, and rotational profiles for merger remnants.

Neutron stars are not the only stars for which general relativity is important. For instance, a possible mechanism for the formation of supermassive black holes in the early universe is the collapse of metal-poor supermassive stars. Rapid spin of these stars could have produced binary black holes.

High-performance computing and software development

General-relativistic simulations are computationally demanding, routinely requiring weeks or months to be completed. For this reason, performance optimization is a serious issue, and even small increases in speed are pursued, as they can shrink the time to obtain an answer by days or even weeks. In addition to this, carefully designed algorithms can enable simulations that would be otherwise prohibitive. For this reason, I have deep interest and solid expertise in high-performance and parallel computing. In my day-to-day life, I develop codes that run on thousands of processors on the most powerful supercomputers in US and Europe.

To be honest, this interest is only a small subset of my broader and long-standing passion for programming and computer science. You can find a list of software I develop or maintain in the Software page.