Johannes Noller

TL;DR: It is shown that the detection of an electromagnetic counterpart to the gravitational-wave signal from the merger of two neutron stars allows for stringent constraints on general scalar-tensor and vector-Tensor theories, while allowing for an independent bound on the graviton mass in bimetric theories of gravity.

TL;DR: There is a persistent interest in extending cosmology beyond the standard model, ΛCDM, motivated by a range of apparently serious theoretical issues, involving such questions as the cosmological constant problem, the particle nature of dark matter, the validity of general relativity on large scales, the existence of anomalies in the CMB and on small scales, and the predictivity and testability of the inflationary paradigm as mentioned in this paper.

TL;DR: There is a persistent interest in extending cosmology beyond the standard model, $\Lambda$CDM as discussed by the authors, motivated by a range of apparently serious theoretical issues, involving such questions as the cosmological constant problem, the particle nature of dark matter, the validity of general relativity on large scales, the existence of anomalies in the CMB and on small scales, and the predictivity and testability of the inflationary paradigm.

TL;DR: In this paper, a family of ways in which matter can couple to one or more ''metrics'/spin-2 fields in the vielbein formulation is constructed subject to the weak equivalence principle and the absence of ghosts from pure spin-2 interactions generated by the matter action.

TL;DR: In this article, the authors show that the quasistatic approximation must be used with some care by studying linearly perturbed scalar field cosmologies and quantifying the errors that arise from taking the quasisistatic limit.