5 papers
Constraints on Coupled Dark Energy in the DESI Era
Adrià Gómez-Valent, Adrià Gómez-Valent, Ziyang Zheng +1
We investigate the current viability of a well-known coupled dark energy scenario in which cold dark matter (DM) interacts with a spin-0 dark energy component through a non-trivial…
Testing the equivalence principle across the Universe: a model-independent approach with galaxy multi-tracing
Sveva Castello, Ziyang Zheng, Camille Bonvin +1
We present a test of the equivalence principle on cosmological scales. This cornerstone of general relativity has been tested with high precision for standard matter, but its valid…
Testing the cosmological Euler equation: viscosity, equivalence principle, and gravity beyond general relativity
Ziyang Zheng, Malte Schneider, Luca Amendola
We investigate how the cosmological Euler equation can be tested in the presence of viscous dark matter, violations of the equivalence principle (EP), and modifications of gravity,…
One-loop kernels in scale-dependent Horndeski theory
Ziyang Zheng, Hanqiong Jia, Bilal Tüdes +3
We investigate the nonlinear evolution of cosmological perturbations in theories with scale-dependent perturbation growth, first in general and then focusing on Horndeski gravity.…
Model-independent forecasts for the cosmological anisotropic stress
Ziad Sakr, Ziyang Zheng, Santiago Casas
The effective anisotropic stress is a key variable in the characterization of many classes of modified gravity theories, as it allows the testing for a long-range force additi…