Baytas, Bekir Bojowald, Martin Crowe, Sean Mielczarek, Jakub

Detailed applications of minisuperspace methods are presented and compared with results obtained in recent years by means of causal dynamical triangulations (CDTs), mainly in the form of effective actions. The analysis sheds light on conceptual questions such as the treatment of time or the role and scaling behavior of statistical and quantum fluct...

Brax, Philippe Valageas, Patrick

We propose a simple model that provides a dynamical cancellation mechanism of the vacuum energy density appearing either in the form of a bare cosmological constant, quantum fluctuations of matter fields or the result of phase transitions. This `conformal compensator model' is based on a conformal coupling $A(\varphi)$ between the Einstein and the ...

Moreau, G. Serreau, J.

We study the backreaction of gravitationally amplified quantum fluctuations of scalar fields on a classical de Sitter geometry. We formulate the problem in the framework of the Wilsonian renormalization group, which allows us to treat the scalar field fluctuations in a nonperturbative manner and to follow the renormalization flow of the spacetime c...

Léonard, F. Delamotte, B. Wschebor, N.

The hierarchy problem in the Standard Model is usually understood as both a technical problem of stability of the calculation of the quantum corrections to the masses of the Higgs sector and of the unnatural difference between the Planck and gauge breaking scales. Leaving aside the gauge sector, we implement on a purely scalar model a mechanism for...

Aron, Camille Biroli, Giulio Cugliandolo, Leticia F.

We unveil the universal (model-independent) symmetry satisfied by Schwinger-Keldysh quantum field theories whenever they describe equilibrium dynamics. This is made possible by a generalization of the Schwinger-Keldysh path-integral formalism in which the physical time can be re-parametrized to arbitrary contours in the complex plane. Strong relati...

Fujita, Tomohiro Namba, Ryo Tada, Yuichiro

We show that a detectable tensor-to-scalar ratio (r≥10−3) on the CMB scale can be generated even during extremely low energy inflation which saturates the BBN bound ρinf≈(30MeV)4 . The source of the gravitational waves is not quantum fluctuations of graviton but those of SU(2) gauge fields, energetically supported by coupled axion fields. The curva...

Douçot, B. Kovrizhin, D. Moessner, R.

We study the role of zero-point quantum fluctuations in a range of magnetic states which on the classical level are close to spin-aligned ferromagnets. These include Skyrmion textures characterized by non-zero topological charge, and topologically-trivial spirals arising from the competition of the Heisenberg and Dzyaloshin-skii–Moriya interactions...

Chamseddine, Ali H. Mukhanov, Viatcheslav

We present a theory of ghost-free massive gravity where the mass of the graviton is generated through the Brout-Englert-Higgs (BEH) mechanism and one of the four scalar fields used is that of mimetic gravity. The mass term is not of the Fierz-Pauli type and the constraint eliminates the Boulware-Deser ghost which is absent to all orders. We perform...

Viennot, David Aubourg, Lucile

We study, by using tools of the dynamical system theory, a fermionic string streched from a non-commutative D2-brane (stack of D0-branes in the BFSS model) to a probe D0-brane as a quantum system driven by a chaotic system, the (classical and quantum) chaos being induced in the D2-brane dynamics by quantum fluctuations. We show that this dynamics w...

Athenodorou, Andreas Boucaud, Philippe de Soto, Feliciano Rodríguez-Quintero, José Zafeiropoulos, Savvas

We report on an instanton-based analysis of the gluon Green functions in the Landau gauge for low momenta; in particular we use lattice results for αs in the symmetric momentum subtraction scheme (MOM) for large-volume lattice simulations. We have exploited quenched gauge field configurations, Nf = 0, with both Wilson and tree-level Symanzik improv...