Zobrazeno 1 - 10
of 112
pro vyhledávání: '"Piva, Marco"'
Autor:
Piva, Marco
We study a class of renormalizable quantum field theories with purely virtual particles that exhibits nonrenormalizable behavior in the high-energy limit of scattering cross sections, which grow as powers of the center-of-mass energy squared and seem
Externí odkaz:
http://arxiv.org/abs/2312.09045
Autor:
Piva, Marco
We consider a self-interacting, massive rank-1 field coupled to quantum gravity. The theory is renormalizable by power counting and contains a massive spin-1 field and a massive scalar field. The latter has a propagator with negative residue and it i
Externí odkaz:
http://arxiv.org/abs/2306.11874
Autor:
Piva, Marco
We review the formulation of quantum field theories with purely virtual particles, a new type of degrees of freedom that can mediate interactions without ever appear as external on-shell states. This property allows to solve the problem of ghosts in
Externí odkaz:
http://arxiv.org/abs/2305.12549
Autor:
Piva, Marco Antonio
A partir da Revolução Sandinista, ocorrida na Nicarágua em 19 de julho de 1979, esta pesquisa analisa a opção do Partido dos Trabalhadores (PT) por uma política internacionalista com foco na América Latina na década de 1980, quando da sua fas
Autor:
Melis, Aurora, Piva, Marco
Quantum field theories with purely virtual particles, or fakeons, require suitable modifications in one-loop integrals. We provide the expressions for the modified scalar integrals in the case of the bubble, triangle and box diagrams. The new functio
Externí odkaz:
http://arxiv.org/abs/2209.05547
Autor:
Piva, Marco
Publikováno v:
Phys. Rev. D 105, 045006 (2022)
We consider massive higher-spin multiplets coupled to quantum gravity and compute their contributions to the gravitational beta functions at one loop. Such theories, if quantized with the Feynman prescription, would contain ghosts. Instead, those deg
Externí odkaz:
http://arxiv.org/abs/2110.09649
Autor:
Anselmi, Damiano, Kannike, Kristjan, Marzo, Carlo, Marzola, Luca, Melis, Aurora, Müürsepp, Kristjan, Piva, Marco, Raidal, Martti
Publikováno v:
Phys. Rev. D 104, 035009 (2021)
Extensions to the Standard Model that use strictly off-shell degrees of freedom - the fakeons - allow for new measurable interactions at energy scales usually precluded by the constraints that target the on-shell propagation of new particles. Here we
Externí odkaz:
http://arxiv.org/abs/2104.03249
Autor:
Anselmi, Damiano, Kannike, Kristjan, Marzo, Carlo, Marzola, Luca, Melis, Aurora, Müürsepp, Kristjan, Piva, Marco, Raidal, Martti
We introduce a new way of modeling the physics beyond the Standard Model by considering fake, strictly off-shell degrees of freedom: the fakeons. To demonstrate the approach and exemplify its reach, we re-analyze the phenomenology of the Inert Double
Externí odkaz:
http://arxiv.org/abs/2104.02071
Publikováno v:
Class. Quantum Grav. 38 (2021) 225011
We study inflation as a "cosmic" renormalization-group flow. The flow, which encodes the dependence on the background metric, is described by a running coupling $\alpha $, which parametrizes the slow roll, a de Sitter free, analytic beta function and
Externí odkaz:
http://arxiv.org/abs/2103.01653
Publikováno v:
J. High Energy Phys. 07 (2020) 211
We derive the predictions of quantum gravity with fakeons on the amplitudes and spectral indices of the scalar and tensor fluctuations in inflationary cosmology. The action is $R+R^{2}$ plus the Weyl-squared term. The ghost is eliminated by turning i
Externí odkaz:
http://arxiv.org/abs/2005.10293