40 citations · 41 across the 9 of their papers we have counts for
12 papers
Hamiltonian analysis of disformally coupled fermions in scalar-tensor theories
Alexander Ganz, Apostolos Tsampodimos
We study disformal transformations of scalar fields coupled to a Dirac fermion. The resulting axial coupling generically introduces higher derivatives in the scalar f…
Unpolarized Low-Frequency Tail of Causal Chiral Gravitational Waves
Tikinas Chabour, Guillem Domènech, Alexander Ganz +1
Parity violation in the early Universe may lead to a chiral gravitational wave background. We show that, for finite-time parity-violating sources, the low-frequency tail of the gen…
Gravitational wave constraints on the Paneitz operator
Robin Valtin, Alexander Ganz, Guillem Domènech
The Paneitz operator is a dimension-4 conformally invariant fourth-order differential operator that has recently attracted attention for possible cancellations of the vacuum energy…
Apparent Lorentz violation from disformally coupled ultralight dark matter
Guillem Domènech, Apostolos Tsabodimos, Apostolos Tsampodimos +3
We study the impact of general disformal metric transformations on fermions, which shift the gravitational metric by an additional rank-2 tensor. This tensor can in principle be co…
On the consistent disformal couplings to fermions
Guillem Domènech, Alexander Ganz, Apostolos Tsabodimos +1
Disformal couplings to fermions lead to a unique derivative coupling to the axial fermionic current, which contains higher derivatives in general. We derive general conditions on c…
Unique gravitational wave signatures of GLPV scalar-tensor theories
Guillem Domènech, Alexander Ganz, Mohammad Ali Gorji +1
We study gravitational waves induced by scalar primordial fluctuations in Gleyzes-Langlois-Piazza-Vernizzi (GLPV), beyond Horndeski, scalar-tensor theories. We uncover, at the leve…
Scalar-assisted magnetogenesis during the radiation-dominated epoch
Alexander Ganz, Chunshan Lin, Mian Zhu
We propose a novel mechanism to generate primordial magnetic fields (PMFs) strong enough to explain the observed cosmic magnetic fields. We employ a scalar field charged under U(1)…
Connecting Relativistic MOND Theories with Mimetic Gravity
Guillem Domènech, Alexander Ganz
We find a connection between relativistic Modified Newtonian Dynamics (MOND) theories and (scalar) mimetic gravity. We first demonstrate that any relativistic MOND model featuring…
Constraining the Gravitational Wave Speed in the Early Universe via Gravitational Cherenkov Radiation
Paola C. M. Delgado, Alexander Ganz, Chunshan Lin +1
Scalar particles traveling faster than a subluminal gravitational wave generate gravitons via gravitational Cherenkov radiation. In this paper, we investigate graviton production b…
Enhanced induced gravitational waves in Horndeski gravity
Guillem Domènech, Alexander Ganz
We study secondary gravitational wave production in Horndenski gravity, when the scalar field dominates the very early universe. We find that higher derivative interactions easily…
Probing modified Hawking evaporation with gravitational waves from the primordial black hole dominated universe
Shyam Balaji, Guillem Domènech, Gabriele Franciolini +2
It has been recently proposed that Hawking evaporation might slow down after a black hole has lost about half of its mass. Such an effect, called "memory burden", is parameterized…
Separating the spectral counterparts in NGC 1275/Perseus cluster in X-rays
Elena Fedorova, Lidiia Zadorozhna, Anatolii Tugay +3
We develop the recipe to separate the spectral counterparts of the AGN NGC 1275 from the emission of the Perseus cluster surrounding it in the spectra observed by Suzaku/XIS camera…