530 citations · 2k across the 27 of their papers we have counts for
11 papers · 1 filter
Cosmological dynamics of multifield dark energy
Johannes R. Eskilt, Yashar Akrami, Adam R. Solomon +1
We numerically and analytically explore the background cosmological dynamics of multifield dark energy with highly nongeodesic or "spinning" field-space trajectories. These extensi…
Multi-field dark energy: cosmic acceleration on a steep potential
Yashar Akrami, Misao Sasaki, Adam R. Solomon +1
We argue that dark energy with multiple fields is theoretically well-motivated and predicts distinct observational signatures, in particular when cosmic acceleration takes place al…
Massive mimetic cosmology
Adam R. Solomon, Valeri Vardanyan, Yashar Akrami
We study the first cosmological implications of the mimetic theory of massive gravity recently proposed by Chamseddine and Mukhanov. This is a novel theory of ghost-free massive gr…
Aller guten Dinge sind drei: Cosmology with three interacting spin-2 fields
Marvin Lüben, Yashar Akrami, Luca Amendola +1
Theories of massive gravity with one or two dynamical metrics generically lack stable and observationally-viable cosmological solutions that are distinguishable from CDM. We con…
Beyond CDM: Problems, solutions, and the road ahead
Philip Bull, Yashar Akrami, Julian Adamek +37
Despite its continued observational successes, there is a persistent (and growing) interest in extending cosmology beyond the standard model, CDM. This is motivated by a range o…
Cosmological viability of massive gravity with generalized matter coupling
Adam R. Solomon, Jonas Enander, Yashar Akrami +3
There is a no-go theorem forbidding flat and closed FLRW solutions in massive gravity on a flat reference metric, while open solutions are unstable. Recently it was shown that this…