24 research outputs found
EuCAPT White Paper: Opportunities and Challenges for Theoretical Astroparticle Physics in the Next Decade
Astroparticle physics is undergoing a profound transformation, due to a
series of extraordinary new results, such as the discovery of high-energy
cosmic neutrinos with IceCube, the direct detection of gravitational waves with
LIGO and Virgo, and many others. This white paper is the result of a
collaborative effort that involved hundreds of theoretical astroparticle
physicists and cosmologists, under the coordination of the European Consortium
for Astroparticle Theory (EuCAPT). Addressed to the whole astroparticle physics
community, it explores upcoming theoretical opportunities and challenges for
our field of research, with particular emphasis on the possible synergies among
different subfields, and the prospects for solving the most fundamental open
questions with multi-messenger observations.Comment: White paper of the European Consortium for Astroparticle Theory
(EuCAPT). 135 authors, 400 endorsers, 133 pages, 1382 reference
Abridged version of the AWMF guideline for the medical clinical diagnostics of indoor mould exposure
Neutrino mass bounds from confronting an effective model with BOSS Lyman-α data
We present an effective model for the one-dimensional Lyman-α flux power spectrum far above the baryonic Jeans scale. The main new ingredient is constituted by a set of two parameters that encode the impact of small, highly non-linear scales on the onedimensional power spectrum on large scales, where it is measured by BOSS. We show that, by marginalizing over the model parameters that capture the impact of the intergalactic medium, the flux power spectrum from both simulations and observations can be described with high precision. The model displays a degeneracy between the neutrino masses and the (unknown, in our formalism) normalization of the flux power spectrum. This degeneracy can be lifted by calibrating one of the model parameters with simulation data, and using input from Planck CMB data. We demonstrate that this approach can be used to extract bounds on the sum of neutrino masses with comparably low numerical effort, while allowing for a conservative treatment of uncertainties from the dynamics of the intergalactic medium. An explorative analysis yields an upper bound of 0.16 eV at 95% C.L. when applied to BOSS data at 3 ≤ z ≤ 4.2. We also forecast that if the systematic and statistical errors will be reduced by a factor two the upper bound will become 0.1 eV at 95% C.L, and 0.056 eV when assuming a 1% error
Neutron star mergers as a probe of modifications of general relativity with finite-range scalar forces
Observations of gravitational radiation from compact binary systems provide
an unprecedented opportunity to test General Relativity in the strong field
dynamical regime. In this paper, we investigate how future observations of
gravitational radiation from binary neutron star mergers might provide
constraints on finite-range forces from a universally coupled massive scalar
field. Such scalar degrees of freedom are a characteristic feature of many
extensions of General Relativity. For concreteness, we work in the context of
metric gravity, which is equivalent to General Relativity and a
universally coupled scalar field with a non-linear potential whose form is
fixed by the choice of . In theories where neutron stars (or other
compact objects) obtain a significant scalar charge, the resulting attractive
finite-range scalar force has implications for both the inspiral and merger
phases of binary systems. We first present an analysis of the inspiral dynamics
in Newtonian limit, and forecast the constraints on the mass of the scalar and
charge of the compact objects for the Advanced LIGO gravitational wave
observatory. We then perform a comparative study of binary neutron star mergers
in General Relativity with those of a one-parameter model of gravity
using fully relativistic hydrodynamical simulations. These simulations
elucidate the effects of the scalar on the merger and post-merger dynamics. We
comment on the utility of the full waveform (inspiral, merger, post-merger) to
probe different regions of parameter space for both the particular model of
gravity studied here and for finite-range scalar forces more generally.Comment: 22 pages, 8 figures. Typos fixed, references added. Updated to match
the version accepted for publishing in PR