## Alessandro Alberto Trani

** Theoretical & Computational Astrophysics **

## GRAVITATIONAL WAVE ASTROPHYSICS

My current research is dedicated to unravelling the mysteries behind **gravitational wave events**, first observed in 2015, **whose astrophysical nature remains unknown**. To address this, I am actively developing new analytic and numerical tools for modeling the evolution of gravitational wave progenitors. The core questions guiding my investigation include:

### How do black hole binaries form and merge?

### Which astrophysical environments nurture them?

### How can we discern their origin from observed gravitational wave signals?

One of the key processes to form coalescing black hole binaries are **dynamical interactions**, which allow binaries to form and to shrink, until gravitational wave radiation makes them merge.

A black hole binary (1,2) and a single black hole (3) meet in a small region of space, and undergo violent gravitational interactions, until one of the **black hole is ejected** and a **new exchanged binary forms**.

The new binary has a gravitational wave coalescence timescale **one million times shorter** than the original one.

Such intense dynamical interactions happen in dense stellar environments known as **star clusters**. My research findings illustrate the impact of these interactions on the characteristics of **spinning binary black holes**, resulting in distinctive signatures observable through gravitational wave detectors.

However, the **complexity** of the three-body problem extends beyond its astrophysical applications. Together with my students, I have authored several papers about the nature of **chaos in the three-body problem**, and how can we solve it using **statistical theories** and **machine learning techniques**.

Below is the famous **figure-of-eight**, one of the few non-hierarchical periodic solutions of the planar three-body problem with equal masses.

## Gallery

## NEWS

**Breakthrough in predicting chaotic outcomes in three-body systems**! The paper I wrote together with graduate student Viraj Manwadkar and Barak Kol, “*Measurement of three-body chaotic absorptivity predicts chaotic outcome distribution*“, was highlighted in phys.org

## ABOUT ME

I am a theoretical and computational astrophysicist, specialized in gravitational dynamics.

I currently hold a Marie Skłodowska-Curie Postdoctoral Fellowship at the Niels Bohr Institute, University of Copenhagen, Denmark.

I am part of the Gravitational Wave Astrophysics group at the Niels Bohr International Academy.

## ShoRT BIO

2017: **Ph.D. in Astrophysics**, International School for Advanced Studies, Trieste, Italy. 2017-2020: **JSPS Postdoctoral Fellow**, The University of Tokyo, Japan. 2020-2022: **Genesis Fellow**, The University of Tokyo, Japan. 2020-2024: **Visiting Scientist**, Okinawa Institute of Science and Technology, Japan. 2022: **Research Center for the Early Universe Fellow**, The University of Tokyo, Japan. 2022-2023: **Senior COFUND Marie Skłodowska-Curie Fellow**, Niels Bohr Institute, Denmark. 2023-2025: **Marie Skłodowska-Curie Fellow**, Niels Bohr Institute, Denmark.