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A new universal property of cosmological gravitational wave anisotropies

Ameek Malhotra · CERN

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About

The anisotropies of the stochastic gravitational wave background, as produced in the early phases of cosmological evolution, can act as a key probe of the primordial universe particle content. We point out a universal property of gravitational wave anisotropies of cosmological origin: for adiabatic initial conditions, their angular power spectrum is insensitive to the equation of state of the cosmic fluid driving the expansion before BBN. Any deviation from this universal behaviour points to the presence of non-adiabatic sources of primordial fluctuations. In this work we prove this general result, and we illustrate its consequences for a representative realisation of initial conditions based on the curvaton scenario. In the case of the simplest curvaton setup, we also find a fourfould enhancement in the cross-correlation between gravitational wave anisotropies and the CMB temperature fluctuations, vis-à-vis the purely adiabatic scenario..

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The talk

  1. A new universal property of cosmological gravitational wave anisotropies 2023-06-02 · 7 min · CERN's player

Credits and licence

Institution
CERN
Department
Eucapt Conferences
Speaker
Ameek Malhotra
Year
2023
Language
English
Source
CERN
Licence
CERN, as CERN states it. CERN's terms
Attribution
© CERN. CERN provides its audiovisual media free of charge for educational and informational use, credited to CERN; this lecture is shown in CERN's own player.
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