Alessandro A. Trani 교수

On 11 February 2016, the LIGO and Virgo scientific collaborations announced the first direct detection of gravitational waves, a signal caught by the LIGO interferometers on 14 September 2015, and produced by the coalescence of two stellar-mass black holes. The discovery represented the beginning of an entirely new way to investigate the Universe. The latest gravitational-wave catalog by LIGO, Virgo and KAGRA brings the total number of gravitational-wave events to 90, and the count is expected t

Abstract We investigate the role of the Keplerian tidal field generated by a supermassive black hole (SMBH) on the three-body dynamics of stellar mass black holes. We consider two scenarios occurring close to the SMBH: the breakup of unstable triples and three-body encounters between a binary and a single. These two cases correspond to the hard and soft binary cases, respectively. The tidal field affects the breakup of triples by tidally limiting the system, so that the triples break earlier wit

ABSTRACT Recent studies indicate that the progenitors of merging black hole (BH) binaries from young star clusters can undergo a common envelope phase just like isolated binaries. If the stars emerge from the common envelope as naked cores, tidal interactions can efficiently synchronize their spins before they collapse into BHs. Contrary to the isolated case, these binary BHs can also undergo dynamical interactions with other BHs in the cluster before merging. The interactions can tilt the binar

ABSTRACT We study chaos and Lévy flights in the general gravitational three-body problem. We introduce new metrics to characterize the time evolution and final lifetime distributions, namely Scramble Density $\mathcal {S}$ and the Lévy flight (LF) index $\mathcal {L}$, that are derived from the Agekyan–Anosova maps and homology radius $R_{\mathcal {H}}$. Based on these metrics, we develop detailed procedures to isolate the ergodic interactions and Lévy flight interactions. This enables us to stu

Context. Dynamical encounters of stellar-mass black holes (BHs) in a disc of compact objects around a supermassive BH (SMBH) can accelerate the formation and coalescence of BH binaries. It has been proposed that binary–single encounters among BHs in such discs can lead to an excess of highly eccentric BH mergers. However, previous studies have neglected how the disc velocity dispersion and the SMBH’s tidal field affect the three-body dynamics. Aims. We investigate the outcomes of binary–single e

We have run direct N-body simulations to investigate the impact of stellar evolution and dynamics on the structural properties of young massive (3x10^4 solar masses) star clusters (SCs) with different metallicities (Z=1, 0.1, 0.01 solar metallicity). Metallicity drives the mass loss by stellar winds and supernovae (SNe), with SCs losing more mass at high metallicity. We have simulated three sets of initial conditions, with different initial relaxation timescale. We find that the evolution of the

We present a novel way of modeling common envelope evolution in binary and few-body systems. We consider the common envelope inspiral as driven by a drag force with a power-law dependence in relative distance and velocity. The orbital motion is resolved either by direct $N$-body integration or by solving the set of differential equations for the orbital elements as derived using perturbation theory. Our formalism can model the eccentricity during the common envelope inspiral, and it gives result

ABSTRACT All the giant planets in the Solar system host a large number of natural satellites. Moons in extrasolar systems are difficult to detect, but a Neptune-sized exomoon candidate has been recently found around a Jupiter-sized planet in the Kepler-1625b system. Due to their relative ease of detection, hot Jupiters (HJs), which reside in close orbits around their host stars with a period of a few days, may be very good candidates to search for exomoons. It is still unknown whether the HJ pop

Abstract In recent years, an increasing amount of attention is being paid to the gravitational few-body problem and its applications to astrophysical scenarios. Among the main reasons for this renewed interest there is large number of newly discovered exoplanets and the detection of gravitational waves. Here, we present two numerical codes to model three- and few-body systems, called tsunami and okinami. The tsunami code is a direct few-body code with algorithmic regularization, tidal forces and

Context. The three-body problem (3BP) poses a longstanding challenge in physics and celestial mechanics. Despite the impossibility of obtaining general analytical solutions, statistical theories have been developed based on the ergodic principle. This assumption is justified by chaos, which is expected to fully mix the accessible phase space of the 3BP. Aims. This study probes the presence of regular (i.e. non-chaotic) trajectories within the 3BP and assesses their impact on statistical escape t

Abstract We present the first overview of the expected quantity of signals that will showcase significant gravitational-wave phase shifts caused by astrophysical environments, considering the upcoming A+ and A# LIGO/Virgo/KAGRA, Cosmic Explorer, and Einstein Telescope detectors. We construct and analyze two general families of dephasing prescriptions with extensions to eccentric sources, as well as collect five specific prescriptions for the fundamental smoking gun physical mechanisms at play in

An investigation was carried out in order to ob-tain a first characterization of traditional Apulian Treccia, a “braid-shaped” mozzarella made from cow’s milk using a natural whey starter (sieroin-nesto). The samples for the study were made at three different dairies. The experimental design contemplated the production of different shaped cheese (Treccia and round-shaped Fior di latte) and the use of different technologies (sieroinnes-to and direct acidification). All the cheese was analyzed to

I present TSUNAMI, a fast and accurate few-body code designed to follow the evolution of self-gravitating systems. The integrator is based on Mikkola & Tanikawa's algorithmic regularization and can easily handle close encounters, highly hierarchical systems, and extreme mass ratios. TSUNAMI includes post-Newtonian corrections and treatment for the equilibrium and dynamical tides, and it is thus suited to follow the evolution of planetary systems and systems of compact remnants. The code impl