370 citations · 2.4k across the 38 of their papers we have counts for
42 papers
Breaking the axion abundance-isocurvature relation: Scale invariance and high-scale inflation
Mariaveronica De Angelis, Javier Rubio
A QCD axion accounting for dark matter through pre-inflationary misalignment is strongly constrained by CMB isocurvature bounds, which place the classic axion window in tension wit…
Nonlocal Gravity, Restricted CPL Dynamics and DESI Constraints
Luca Amendola, Ismael Ayuso, Amlan Chakraborty +2
Nonlocal modifications of gravity provide a theoretically motivated framework in which cosmic acceleration can emerge dynamically without introducing a fundamental cosmological con…
The Goldstone Awakens: Unimodular dark energy in scale-invariant gravity
Mariaveronica De Angelis, Javier Rubio
We construct an cosmology based on scale invariance and unimodular gravity in which the Goldstone boson of dilatations establishes a predictive connection between inflation a…
Observational Constraints on Early Coupled Quintessence
Lisa W. K. Goh, Joan Bachs-Esteban, Adrià Gómez-Valent +2
We investigate an Early Coupled Quintessence model where a light scalar mediates a fifth force stronger than gravity among dark matter particles and leads to the growth of perturba…
The geometry of inflationary observables: lifts, flows, equivalence classes
Georgios K. Karananas, Marco Michel, Javier Rubio
The Eisenhart lift allows to formulate the dynamics of a scalar field in a potential as pure geodesic motion in a curved field-space manifold involving an additional fictitious vec…
Ricci Reheating Reloaded
Giorgio Laverda, Javier Rubio
A Hubble-induced phase transition is a natural spontaneous symmetry breaking mechanism allowing for explosive particle production in non-oscillatory models of inflation involving n…
Preheating in Einstein-Cartan Higgs Inflation: Oscillon formation
Matteo Piani, Javier Rubio
We make use of classical lattice simulations in 3 + 1 dimensions to study the preheating stage of Higgs Inflation in Einstein-Cartan gravity. Focusing for concreteness on a simplif…
Higgs-Dilaton Inflation in Einstein-Cartan gravity
Matteo Piani, Javier Rubio
We study the phenomenology of the Higgs-Dilaton model in the context of Einstein-Cartan gravity, focusing on the separate impact of the Holst and Nieh-Yan terms on the inflationary…
Cosmology and direct detection of the Dark Axion Portal
Juan Cortabitarte Gutiérrez, Bradley J. Kavanagh, Núria Castelló-Mor +4
The Dark Axion Portal provides a model for Dark Matter (DM) in which both Dark Photons and Axions can contribute to the present day abundance of DM. We study the par…
EuCAPT White Paper: Opportunities and Challenges for Theoretical Astroparticle Physics in the Next Decade
R. Alves Batista, M. A. Amin, G. Barenboim +134
Astroparticle physics is undergoing a profound transformation, due to a series of extraordinary new results, such as the discovery of high-energy cosmic neutrinos with IceCube, the…
Hubble-induced phase transitions on the lattice with applications to Ricci reheating
Dario Bettoni, Asier Lopez-Eiguren, Javier Rubio
Using 3+1 classical lattice simulations, we follow the symmetry breaking pattern and subsequent non-linear evolution of a spectator field non-minimally coupled to gravity when the…
On the impact of non-local gravity on compact stars
Grigoris Panotopoulos, Javier Rubio, Ilídio Lopes
We study the impact of non-local modifications of General Relativity on stellar structure. In particular, assuming an analytic distortion function and specific equations of state,…
Chiral gravitational waves and primordial black holes in UV-protected Natural Inflation
Juan P. Beltrán Almeida, Nicolás Bernal, Dario Bettoni +1
We consider an UV-protected Natural Inflation scenario involving Chern-Simons-like interactions between the inflaton and some beyond the Standard Model gauge fields. The accelerate…
One residue to rule them all: Electroweak symmetry breaking, inflation and field-space geometry
Georgios K. Karananas, Marco Michel, Javier Rubio
We point out that the successful generation of the electroweak scale via gravitational instanton configurations in certain scalar-tensor theories can be viewed as the aftermath of…
UV Freeze-in in Starobinsky Inflation
Nicolás Bernal, Javier Rubio, Hardi Veermäe
In the Starobinsky model of inflation, the observed dark matter abundance can be produced from the direct decay of the inflaton field only in a very narrow spectrum of close-to-con…
Boosting Ultraviolet Freeze-in in NO Models
Nicolás Bernal, Javier Rubio, Hardi Veermäe
We present a novel UV freeze-in mechanism for enhancing the dark matter abundance in cosmologies where inflation is followed by an epoch dominated by a fluid stiffer than radiation…
Scale symmetry, the Higgs and the Cosmos
Javier Rubio
I review the Higgs-Dilaton model: a scale-invariant extension of the Standard Model and gravity able to support inflation and dark energy with just an additional degree of freedom…
Hubble-induced phase transitions: Walls are not forever
Dario Bettoni, Javier Rubio
The interplay between non-minimally coupled scalar fields and a kinetic-dominated era following the end of inflation triggers the spontaneous symmetry breaking of internal symmetri…
Primordial dark matter halos from fifth forces
Stefano Savastano, Luca Amendola, Javier Rubio +1
We argue that primordial dark matter halos could be generated during radiation domination by long range attractive forces stronger than gravity. In this paper we derive the conditi…
Electromagnetic probes of primordial black holes as dark matter
Y. Ali-Haimoud, S. Clesse, J. Garcia-Bellido +91
The LIGO discoveries have rekindled suggestions that primordial black holes (BHs) may constitute part to all of the dark matter (DM) in the Universe. Such suggestions came from 1)…
Preheating in Palatini Higgs inflation
Javier Rubio, Eemeli S. Tomberg
We study the details of preheating in Palatini Higgs inflation. We show, that contrary to what happens in the metric formulation of the model, the Universe does not reheat through…
Hidden Inflaton Dark Matter
Juan P. Beltrán Almeida, Nicolás Bernal, Javier Rubio +1
If cosmic inflation was driven by an electrically neutral scalar field stable on cosmological time scales, the field necessarily constitutes all or part of dark matter (DM). We stu…
Mimicking alternatives to inflation with interacting spectator fields
Guillem Domènech, Javier Rubio, Julius Wons
It has been argued that oscillatory features from spectator fields in the primordial power spectrum could be a probe of alternatives to inflation. In this work, we soften this clai…
Scale-invariant alternatives to general relativity. III. The inflation--dark-energy connection
Santiago Casas, Georgios K. Karananas, Martin Pauly +1
We discuss the cosmological phenomenology of biscalar-tensor models displaying a maximally symmetric Einstein-frame kinetic sector and constructed on the basis of scale symmetry an…