Search

Your search keyword '"Racco D."' showing total 3 results
Start Over Author "Racco D." Database Academic Search Index
3 results on '"Racco D."'

1. Primordial black holes from Higgs vacuum instability: avoiding fine-tuning through an ultraviolet safe mechanism.

Author

Espinosa, J. R., Racco, D., and Riotto, A.

Subjects
*BLACK holes, *HIGGS bosons, *DARK matter, *SCALAR field theory, *ULTRAVIOLET radiation
Abstract

We have recently proposed the idea that dark matter in our universe is formed by primordial black holes generated by Standard Model Higgs fluctuations during inflation and thanks to the fact that the Standard Model Higgs potential develops an instability at a scale of the order of 1011 GeV. In this sense, dark matter does not need any physics beyond the Standard Model, although the mechanism needs fine-tuning to avoid the overshooting of the Higgs into the dangerous AdS vacuum. We show how such fine-tuning can be naturally avoided by coupling the Higgs to a very heavy scalar with mass ≫1011 GeV that stabilises the potential in the deep ultraviolet, but preserving the basic feature of the mechanism which is built within the Standard Model. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

2. Cosmological Signature of the Standard Model Higgs Vacuum Instability: Primordial Black Holes as Dark Matter.

Author

Espinosa, J. R., Racco, D., and Riotto, A.

Subjects
*HIGGS bosons, *BLACK holes, *DARK matter
Abstract

For the current central values of the Higgs boson and top quark masses, the standard model Higgs potential develops an instability at a scale of the order of 1011 GeV. We show that a cosmological signature of such instability could be dark matter in the form of primordial black holes seeded by Higgs fluctuations during inflation. The existence of dark matter might not require physics beyond the standard model. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

3. Testing primordial black holes as dark matter with LISA.

Author

Bartolo, N., De Luca, V., Franciolini, G., Peloso, M., Racco, D., and Riotto, A.

Subjects
*DARK matter, *BLACK holes, *GRAVITATIONAL waves, *INFLATIONARY universe, *RADIATION, *CURVATURE
Abstract

The idea that primordial black holes (PBHs) can comprise most of the dark matter of the Universe has recently reacquired a lot of momentum. Observational constraints, however, rule out this possibility for most of the PBH masses, with a notable exception around 10-12 M⊙. These light PBHs may be originated when a sizable comoving curvature perturbation generated during inflation reenters the horizon during the radiation phase. During such a stage, it is unavoidable that gravitational waves (GWs) are generated. Since their source is quadratic in the curvature perturbations, these GWs are generated fully non-Gaussian. Their frequency today is about a millihertz, which is exactly the range where the LISA mission has the maximum of its sensitivity. This is certainly an impressive coincidence. We show that this scenario of PBHs as dark matter can be tested by LISA by measuring the GW two-point correlator. On the other hand, we show that the short observation time (as compared to the age of the Universe) and propagation effects of the GWs across the perturbed Universe from the production point to the LISA detector suppress the bispectrum to an unobservable level. This suppression is completely general and not specific to our model. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results