Fabio Capela - Academia.edu (original) (raw)
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Papers by Fabio Capela
By considering adiabatic contraction of the dark matter (DM) during star formation, we estimate t... more By considering adiabatic contraction of the dark matter (DM) during star formation, we estimate the amount of DM trapped in stars at their birth. If the DM consists partly of primordial black holes (PBHs), they will be trapped together with the rest of the DM and will be finally inherited by a star compact remnant --- a white dwarf (WD) or a neutron star (NS), which they will destroy in a short time. Observations of WDs and NSs thus impose constraints on the abundance of PBH. We show that the best constraints come from WDs and NSs in globular clusters which exclude the DM consisting entirely of PBH in the mass range 10^16 g - 3× 10^22 g, with the strongest constraint on the fraction Ω_ PBH /Ω_ DM≲ 10^-2 being in the range of PBH masses 10^17 g - 10^18 g.
Keywords: Philosophie ; Epistemologie et histoire des sciences ; Section PH Reference EPFL-STUDEN... more Keywords: Philosophie ; Epistemologie et histoire des sciences ; Section PH Reference EPFL-STUDENT-164082 Record created on 2011-03-06, modified on 2017-05-12
This thesis is divided in two parts: the first part is dedicated to the study of black hole solut... more This thesis is divided in two parts: the first part is dedicated to the study of black hole solutions in a theory of modified gravity, called massive gravity, that may be able to explain the actual stage of accelerated expansion of the Universe, while in the second part we focus on constraining primordial black holes as dark matter candidates.In particular, during the first part we study the thermodynamical properties of specific black hole solutions in massive gravity. We conclude that such black hole solutions do not follow the second and third of law of thermodynamics, which may signal a problem in the model. For instance, a naked singularity may be created as a result of the evolution of a singularity-free state.In the second part, we constrain primordial black holes as dark matter candidates. To do that, we consider the effect of primordial black holes when they interact with compact objects, such as neutron stars and white dwarfs. The idea is as follows: if a primordial black ...
ArXiv, 2019
Prediction of molecular properties, including physico-chemical properties, is a challenging task ... more Prediction of molecular properties, including physico-chemical properties, is a challenging task in chemistry. Herein we present a new state-of-the-art multitask prediction method based on existing graph neural network models. We have used different architectures for our models and the results clearly demonstrate that multitask learning can improve model performance. Additionally, a significant reduction of variance in the models has been observed. Most importantly, datasets with a small amount of data points reach better results without the need of augmentation.
Proceedings of The 34th International Cosmic Ray Conference — PoS(ICRC2015), Aug 18, 2016
that may invalidate the result.
Journal of Cosmology and Astroparticle Physics, 2015
Journal of High Energy Physics, 2011
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012
By considering adiabatic contraction of the dark matter (DM) during star formation, we estimate t... more By considering adiabatic contraction of the dark matter (DM) during star formation, we estimate the amount of DM trapped in stars at their birth. If the DM consists partly of primordial black holes (PBHs), they will be trapped together with the rest of the DM and will be finally inherited by a star compact remnant --- a white dwarf (WD) or a neutron star (NS), which they will destroy in a short time. Observations of WDs and NSs thus impose constraints on the abundance of PBH. We show that the best constraints come from WDs and NSs in globular clusters which exclude the DM consisting entirely of PBH in the mass range 10^16 g - 3× 10^22 g, with the strongest constraint on the fraction Ω_ PBH /Ω_ DM≲ 10^-2 being in the range of PBH masses 10^17 g - 10^18 g.
Keywords: Philosophie ; Epistemologie et histoire des sciences ; Section PH Reference EPFL-STUDEN... more Keywords: Philosophie ; Epistemologie et histoire des sciences ; Section PH Reference EPFL-STUDENT-164082 Record created on 2011-03-06, modified on 2017-05-12
This thesis is divided in two parts: the first part is dedicated to the study of black hole solut... more This thesis is divided in two parts: the first part is dedicated to the study of black hole solutions in a theory of modified gravity, called massive gravity, that may be able to explain the actual stage of accelerated expansion of the Universe, while in the second part we focus on constraining primordial black holes as dark matter candidates.In particular, during the first part we study the thermodynamical properties of specific black hole solutions in massive gravity. We conclude that such black hole solutions do not follow the second and third of law of thermodynamics, which may signal a problem in the model. For instance, a naked singularity may be created as a result of the evolution of a singularity-free state.In the second part, we constrain primordial black holes as dark matter candidates. To do that, we consider the effect of primordial black holes when they interact with compact objects, such as neutron stars and white dwarfs. The idea is as follows: if a primordial black ...
ArXiv, 2019
Prediction of molecular properties, including physico-chemical properties, is a challenging task ... more Prediction of molecular properties, including physico-chemical properties, is a challenging task in chemistry. Herein we present a new state-of-the-art multitask prediction method based on existing graph neural network models. We have used different architectures for our models and the results clearly demonstrate that multitask learning can improve model performance. Additionally, a significant reduction of variance in the models has been observed. Most importantly, datasets with a small amount of data points reach better results without the need of augmentation.
Proceedings of The 34th International Cosmic Ray Conference — PoS(ICRC2015), Aug 18, 2016
that may invalidate the result.
Journal of Cosmology and Astroparticle Physics, 2015
Journal of High Energy Physics, 2011
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012