Zobrazeno 1 - 10
of 107
pro vyhledávání: '"Villadoro, Giovanni"'
We show that if dark matter consists of QCD axions in the post-inflationary scenario more than ten percent of it efficiently collapses into Bose stars at matter-radiation equality. Such a result is mostly independent of the present uncertainties on t
Externí odkaz:
http://arxiv.org/abs/2405.19389
We strengthen the cosmological bound on the axion mass, by solving the momentum-dependent Boltzmann equations for axion-pion scatterings and by using a phenomenological production rate derived from pion-pion scattering data, overcoming the breakdown
Externí odkaz:
http://arxiv.org/abs/2211.03799
Publikováno v:
SciPost Phys. 10, 050 (2021)
We study the contribution to the QCD axion dark matter abundance that is produced by string defects during the so-called scaling regime. Clear evidence of scaling violations is found, the most conservative extrapolation of which strongly suggests a l
Externí odkaz:
http://arxiv.org/abs/2007.04990
We extend the study of the two-dimensional euclidean $\phi^4$ theory initiated in ref. [1] to the $\mathbb Z_2$ broken phase. In particular, we compute in perturbation theory up to N$^4$LO in the quartic coupling the vacuum energy, the vacuum expecta
Externí odkaz:
http://arxiv.org/abs/1901.05023
Autor:
Gorghetto, Marco, Villadoro, Giovanni
We improve the precision of the topological susceptibility of QCD, and therefore of the QCD axion mass, by including $O(\alpha_{\rm em})$ and NNLO corrections in the chiral expansion, which amount to 0.65(21)% and -0.71(29)% respectively. Both correc
Externí odkaz:
http://arxiv.org/abs/1812.01008
We study the system of axion strings that forms in the early Universe if the Peccei-Quinn symmetry is restored after inflation. Using numerical simulations, we establish the existence of an asymptotic solution to which the system is attracted indepen
Externí odkaz:
http://arxiv.org/abs/1806.04677
Perturbation theory of a large class of scalar field theories in $d<4$ can be shown to be Borel resummable using arguments based on Lefschetz thimbles. As an example we study in detail the $\lambda \phi^4$ theory in two dimensions in the $Z_2$ symmet
Externí odkaz:
http://arxiv.org/abs/1805.05882
We study quantum mechanical systems with a discrete spectrum. We show that the asymptotic series associated to certain paths of steepest-descent (Lefschetz thimbles) are Borel resummable to the full result. Using a geometrical approach based on the P
Externí odkaz:
http://arxiv.org/abs/1702.04148
Autor:
Bonati, Claudio, D'Elia, Massimo, Mariti, Marco, Martinelli, Guido, Mesiti, Michele, Negro, Francesco, Sanfilippo, Francesco, Villadoro, Giovanni
The properties of the QCD axion are strictly related to the dependence of strong interactions on the topological parameter theta. We present a determination of the topological properties of QCD for temperatures up to around 600 MeV, obtained by latti
Externí odkaz:
http://arxiv.org/abs/1612.06269
Publikováno v:
Phys. Rev. D 96, 021701 (2017)
In quantum mechanics and quantum field theory perturbation theory generically requires the inclusion of extra contributions non-perturbative in the coupling, such as instantons, to reproduce exact results. We show how full non-perturbative results ca
Externí odkaz:
http://arxiv.org/abs/1612.04376