Zobrazeno 1 - 10
of 41
pro vyhledávání: '"Ripken, Chris"'
Autor:
Ferrero, Renata, Ripken, Chris
Publikováno v:
JHEP 08 (2023) 199
We employ a manifestly covariant formalism to compute the tree-level amputated Green's function of non-minimally coupled scalar fields in quadratic gravity in a de Sitter background. We study this Green's function in the adiabatic limit, and construc
Externí odkaz:
http://arxiv.org/abs/2212.08052
Asymptotic Safety implies that observables including scattering amplitudes remain finite at the highest energy scales. Traditionally, this feature is connected to an interacting fixed point of the Wilsonian renormalization group that provides the hig
Externí odkaz:
http://arxiv.org/abs/2210.16072
The effective action includes all quantum corrections arising in a given quantum field theory. Thus it serves as a powerful generating functional from which quantum-corrected scattering amplitudes can be constructed via tree-level computations. In th
Externí odkaz:
http://arxiv.org/abs/2205.01738
Autor:
Ferrero, Renata, Ripken, Chris
Publikováno v:
SciPost Phys. 13, 106 (2022)
We present a covariant framework to compute scattering amplitudes and potentials in a de Sitter background. In this setting, we compute the potential of a graviton-mediated scattering process involving two very massive scalars at tree level. Although
Externí odkaz:
http://arxiv.org/abs/2112.03766
Form factors constitute the key building block when organising the gravitational dynamics in terms of a curvature expansion. They generalise the concept of momentum-dependent couplings to curved spacetime. Moreover, they may capture modifications of
Externí odkaz:
http://arxiv.org/abs/2111.12365
Autor:
Knorr, Benjamin, Ripken, Chris
Publikováno v:
Phys. Rev. D 103, 105019 (2021)
Affine gravity is a connection-based formulation of gravity that does not involve a metric. After a review of basic properties of affine gravity, we compute the tree-level scattering amplitude of scalar particles interacting gravitationally via the c
Externí odkaz:
http://arxiv.org/abs/2012.05144
We employ the curvature expansion of the quantum effective action for gravity-matter systems to construct graviton-mediated scattering amplitudes for non-minimally coupled scalar fields in a Minkowski background. By design, the formalism parameterise
Externí odkaz:
http://arxiv.org/abs/2007.04396
Publikováno v:
Phys. Rev. Lett. 125, 181301 (2020)
We study the gravity-mediated scattering of scalar fields based on a parameterisation of the Lorentzian quantum effective action. We demonstrate that the interplay of infinite towers of spin zero and spin two poles at imaginary squared momentum leads
Externí odkaz:
http://arxiv.org/abs/2007.00733
Over the last years the Asymptotic Safety program has matured into a serious candidate for a quantum theory of gravity compatible with observations. The rapid technical progress in computing renormalisation group flows for gravity and gravity-matter
Externí odkaz:
http://arxiv.org/abs/1907.02903
The asymptotic safety program strives for a consistent description of gravity as a non-perturbatively renormalizable quantum field theory. In this framework the gravitational interactions are encoded in a renormalization group flow connecting the qua
Externí odkaz:
http://arxiv.org/abs/1901.01731