activity
20242026
collaborators

6 papers

astro-ph.CO2026

Constraining dark energy with complementary probes of large-scale structure

Neel Shah, Kazuya Koyama, Johannes Noller +1

To observationally pin down the nature of dark energy, it is essential to consistently model cosmological perturbations in the presence of dark energy alongside the background expa…

gr-qc2026

Testing Dark Energy with Black Hole Ringdown

Laurens Smulders, Johannes Noller, Sergi Sirera

We show that dynamical dark energy theories can imprint modifications on the quasi-normal mode (QNM) spectrum characterising black hole ringdown. The time dependence of dyna…

gr-qc2026

Stable black hole solutions with cosmological hair

Laurens Smulders, Johannes Noller

Dynamical dark energy theories generically introduce a time-dependent field that causes the accelerated expansion of the Universe on large scales. When embedding black hole solutio…

gr-qc2026

Inverting no-hair theorems: How requiring General Relativity solutions restricts scalar-tensor theories

Hajime Kobayashi, Shinji Mukohyama, Johannes Noller +3

Black hole solutions in general scalar-tensor theories are known to permit hair, i.e. non-trivial scalar profiles and/or metric solutions different from the ones of General Relativ…

gr-qc2025

Stability and quasinormal modes for black holes with time-dependent scalar hair

Sergi Sirera, Johannes Noller

We investigate black hole solutions with time-dependent (scalar) hair in scalar-tensor theories. Known exact solutions exist for such theories at the background level, where the me…

astro-ph.CO2024

Constraining dark energy with the integrated Sachs-Wolfe effect

Emeric Seraille, Johannes Noller, Blake D. Sherwin

We use the integrated Sachs-Wolfe (ISW) effect, by now detectable at within the context of CDM cosmologies, to place strong constraints on dynamical dark energy theo…