Related papers: Stellar triples with chemically homogeneously evol…
The first generation of stars, known as Population III (Pop III), played a crucial role in the early Universe through their unique formation environment and metal-free composition. These stars can undergo chemically homogeneous evolution…
Black hole (BH) mergers driven by gravitational perturbations of external companions constitute an important class of formation channels for merging BH binaries detected by LIGO. We have studied the orbital and spin evolution of binary BHs…
Galactic double white dwarfs will be prominent gravitational-wave sources for the Laser Interferometer Space Antenna (LISA). While previous studies have primarily focused on formation scenarios in which binaries form and evolve in…
The evolution of main sequence binaries that reside in the Galactic Centre can be heavily influenced by the central supermassive black hole (SMBH). Due to these perturbative effects, the stellar binaries in dense environments are likely to…
As the number of observed merging binary black holes (BHs) grows, accurate models are required to disentangle multiple formation channels. In models with isolated binaries, important uncertainties remain regarding the stability of mass…
Based on astrometric measurements and spectral analysis from $Gaia$ DR3, two quiescent black hole (BH) binaries, $Gaia$ BH1 and BH2, have been identified. Their origins remain controversial, particularly for $Gaia$ BH1. By considering a…
Most studies of mass transfer in binary systems assume circular orbits at the onset of Roche lobe overflow. However, there are theoretical and observational indications that mass transfer could occur in eccentric orbits. In particular,…
The recent discovery of a gravitational wave from the merging of two black holes of about 30 solar masses each challenges our incomplete understanding of massive stars and their evolution. Critical ingredients comprise mass-loss, rotation,…
We study the evolution of populations of binary stars within massive cluster-forming regions. We simulate the formation of young massive star clusters within giant molecular clouds with masses ranging from 2 x 10$^{4}$ to 3.2 x 10$^{5}$…
In order to understand the rate of merger of stellar-mass black hole binaries (BHBs) by gravitational wave (GW) emission it is important to determine the major pathways to merger. We use numerical simulations to explore the evolution of…
We investigate how the multiplicity of binary, triple and quadruple star systems changes as the systems evolve from the zero-age main-sequence to the Hubble time. We find the change in multiplicity fractions over time for each data set,…
Depending on the stellar type, more than $\sim 50$\% and $\sim 15\%$ of stars in the field have at least one and two stellar companions, respectively. Hierarchical systems can be assembled dynamically in dense star clusters, as a result of…
We discuss some aspects of stellar evolution in binary systems. While single stars can swell following the chemical evolution of their interior, stars belonging to binary systems cannot overflow the size of the Roche lobe and hydrostatic…
[Abridged] We present a new grid of massive population III star models including the effects of rotation on the stellar structure and chemical mixing, and magnetic torques for the transport of angular momentum. Based on the grid, we also…
Massive stars are often found in multiple systems, yet how binary-star systems with very close separations ($\lesssim$ au) assemble remains unresolved. We investigate the formation and inward migration of massive-star binaries in…
We compute the isotropic gravitational wave (GW) background produced by binary supermassive black holes (SBHs) in galactic nuclei. In our model, massive binaries evolve at early times via gravitational-slingshot interaction with nearby…
Tight Triple Systems have stars in a hierarchical configuration with a third star orbiting the inner binary with a period of fewer than 1000 days. Such systems are important for understanding the formation and evolution of stars in multiple…
Numerical simulations have now shown that Population III (Pop III) stars can form in binaries and small clusters and that these stars can be in close proximity to each other. If so, they could be subject to binary interactions such as mass…
Many close stellar binaries are accompanied by a far-away star. The "eccentric Kozai-Lidov" (EKL) mechanism can cause dramatic inclination and eccentricity fluctuations, resulting in tidal tightening of inner binaries of triple stars. We…
Context: Population III (Pop III) stars may be fast rotating. An expected consequence of fast rotation is strong internal mixing that deeply affects their evolutionary tracks in the Hertzsprung-Russell diagram and hence their ionising…