540 citations · 2.4k across the 44 of their papers we have counts for
20 papers · 1 filter
The End of the First Act: Spectral Running, Interacting Dark Radiation, and the Hubble Tension in Light of ACT DR6 Data
Mathias Garny, Florian Niedermann, Martin S. Sloth
We point out that constraints on reported by the ACT collaboration in their DR6 data release are surprisingly sensitive to the assumptions made about the initial…
Dark Acoustic Oscillations and the Hubble Tension
Mathias Garny, Florian Niedermann, Martin S. Sloth
The Hubble tension and the recently reported anomaly in data from the Dark Energy Spectroscopic Instrument (DESI) are considered to pose serious challenges to the standard CDM m…
Dark Acoustic Oscillations as an Early-Universe Explanation of the DESI Anomaly
Mathias Garny, Florian Niedermann, Martin S. Sloth
DESI DR2 data have been widely interpreted as evidence for late-time evolving dark energy (DE) with an apparent phantom crossing. Here we investigate an alternative explanation, ba…
String-induced vacuum decay and its gravitational wave signatures
Aleksandr Chatrchyan, Florian Niedermann, Phoebe Richman-Taylor
False vacuum decay typically proceeds via the nucleation of spherical bubbles of true vacuum, described by symmetric field configurations in Euclidean time. In this work, we…
Hot New Early Dark Energy: Dark Radiation Matter Decoupling
Mathias Garny, Florian Niedermann, Henrique Rubira +1
We present a microscopic model of the dark sector that resolves the Hubble tension within standard current data sets (Planck 2018, Pantheon+ and DESI DR2 BAO) based on well-known f…
The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
Eleonora Di Valentino, Jackson Levi Said, Adam Riess +533
The standard model of cosmology has provided a good phenomenological description of a wide range of observations both at astrophysical and cosmological scales for several decades.…
Confronting Cold New Early Dark Energy and its Equation of State with Updated CMB, Supernovae, and BAO Data
Aleksandr Chatrchyan, Florian Niedermann, Vivian Poulin +1
Cold New Early Dark Energy (Cold NEDE) addresses the Hubble tension through a triggered vacuum phase transition in the dark sector. In this paper, we constrain a phenomenological f…
Hot New Early Dark Energy bridging cosmic gaps: Supercooled phase transition reconciles (stepped) dark radiation solutions to the Hubble tension with BBN
Mathias Garny, Florian Niedermann, Henrique Rubira +1
We propose a simple model that can alleviate the tension while remaining consistent with big bang nucleosynthesis (BBN). It is based on a dark sector described by a standard…
NANOGrav meets Hot New Early Dark Energy and the origin of neutrino mass
Juan S. Cruz, Florian Niedermann, Martin S. Sloth
It has recently been speculated that the NANOGrav observations point towards a first-order phase transition in the dark sector at the GeV scale [1]. Here, we show that such a phase…
Cold New Early Dark Energy pulls the trigger on the and tensions: a simultaneous solution to both tensions without new ingredients
Juan S. Cruz, Florian Niedermann, Martin S. Sloth
In this work, we show that the Cold New Early Dark Energy (Cold NEDE) model in its original form can solve both the Hubble tension and the tension without adding any new ingr…
Profiling Cold New Early Dark Energy
Juan S. Cruz, Steen Hannestad, Emil Brinch Holm +3
Recent interest in New Early Dark Energy (NEDE), a cosmological model with a vacuum energy component decaying in a triggered phase transition around recombination, has been sparked…
A grounded perspective on New Early Dark Energy using ACT, SPT, and BICEP/Keck
Juan S. Cruz, Florian Niedermann, Martin S. Sloth
We examine further the ability of the New Early Dark Energy model (NEDE) to resolve the current tension between the Cosmic Microwave Background (CMB) and local measurements of $H_0…
Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
Elcio Abdalla, Guillermo Franco Abellán, Amin Aboubrahim +200
In this paper we will list a few important goals that need to be addressed in the next decade, also taking into account the current discordances between the different cosmological…
New Early Dark Energy is compatible with current LSS data
Florian Niedermann, Martin S. Sloth
Recently a full-shape analysis of large-scale structure (LSS) data was employed to provide new constraints on a class of Early Dark Energy (EDE) models. In this note, we derive sim…
Cosmology Intertwined IV: The Age of the Universe and its Curvature
Eleonora Di Valentino, Luis A. Anchordoqui, Ozgur Akarsu +88
A precise measurement of the curvature of the Universe is of primeval importance for cosmology since it could not only confirm the paradigm of primordial inflation but also help in…
Cosmology Intertwined III: and
Eleonora Di Valentino, Luis A. Anchordoqui, Ozgur Akarsu +89
The standard Cold Dark Matter cosmological model provides a wonderful fit to current cosmological data, but a few tensions and anomalies became statistically significant with t…
Cosmology Intertwined II: The Hubble Constant Tension
Eleonora Di Valentino, Luis A. Anchordoqui, Ozgur Akarsu +90
The current cosmological probes have provided a fantastic confirmation of the standard Cold Dark Matter cosmological model, that has been constrained with unprecedented accurac…
Cosmology Intertwined I: Perspectives for the Next Decade
Eleonora Di Valentino, Luis A. Anchordoqui, Ozgur Akarsu +89
The standard Cold Dark Matter cosmological model provides an amazing description of a wide range of astrophysical and astronomical data. However, there are a few big open quest…
Resolving the Hubble Tension with New Early Dark Energy
Florian Niedermann, Martin S. Sloth
New Early Dark Energy (NEDE) is a component of vacuum energy at the electron volt scale, which decays in a first-order phase transition shortly before recombination [arXiv:1910.107…
New Early Dark Energy
Florian Niedermann, Martin S. Sloth
New measurements of the expansion rate of the Universe have plunged the standard model of cosmology into a severe crisis. In this letter, we propose a simple resolution to the prob…