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B. B. Martins

Publications and source records attributed to B. B. Martins.

2 recordsLinked to original sources

The Galactic Black Hole mass distribution

The population of extragalactic black holes has been significantly expanded and better understood since the first detection of gravitational waves. Over the past decade, approximately 290 events have been confirmed to involve at least one black hole. In contrast, the galactic black hole population has grown at a much slower pace, with only 42 systems possessing mass estimates, while the vast majority remain as candidates. In this work, we present the first update of a Bayesian analysis of the mass distribution of galactic black holes since 2011, previously based on a sample of 15 low-mass X-ray binaries and 5 high-mass X-ray binaries. Our update includes 28 low-mass X-ray binaries, 6 high-mass X-ray binaries, 7 detached binaries and 1 isolated black hole, also present in the living catalog \textit{CatNoir} which we introduce. We apply a Bayesian framework using five parametric models -- Gaussian, two-Gaussian, log-normal, power-law, and decaying exponential -- and compare their performance in fitting the observed data. Furthermore, we inspect the effect of removing model-dependent systems from the sample. Our results suggest that the power law better describes the Combined sample, while the Gaussian is preferred for the LMXB-only sample, closely followed by the two-Gaussian and log-normal. We derive the $1\%$-quantile of the preferred model's posterior predictive distribution to access information about the lower mass gap. For the Combined and LMXB Samples, we find $M_{1\%} > 4.06\,M_\odot$ and $M_{1\%} > 2.56\,M_\odot$ (at $90\%$ C.I.), respectively. The LMXB result allows for the existence of a sparsely populated Gap, instead of a completely empty one.

astro-ph.HE↗

Energy as a Primitive Ontology for the Physical World

We reanalyze from a modern perspective the bold idea of G. Helm, W. Ostwald, P. Duhem and others that energy is the fundamental entity composing the physical world. We start from a broad perspective reminding the search for a fundamental ``substance'' (perhaps better referred to as ous\'ıa, the original Greek word) from the pre-Socratics to the important debate between Ostwald and Boltzmann about the energy vs. atoms at the end of the 19th century. While atoms were eventually accepted (even by Ostwald himself), the emergence of Quantum Mechanics and Relativity were crucial to suggest that the dismissal of energy in favor of atoms was perhaps premature, and should be revisited. We discuss how the so-called primitive ontology programme can be implemented with energy as the fundamental entity, and why fields (and their quanta, particles) should rather be considered as non-fundamental. We sketch some of the difficulties introduced by the attempt to include gravitation in the general scheme.

physics.hist-ph↗