Cosmologically coupled black holes

Stochastic gravitational wave background from cosmologically coupled black holes paper published in Scientific Reports!

My paper with Marco Calzà, Francesco Gianesello, and Max Rinaldi, where we study the stochastic gravitational wave background signal resulting from inspiraling cosmologically coupled BHs (see this earlier news item), has now officially been published in Scientific Reports (making this my third proper Nature publication)! The full bibliographic coordinates for the paper are Sci. Rep. 14 (2024) 31296. Here is the link to the paper (which is published Open Access).

Stochastic gravitational wave background from cosmologically coupled black holes paper accepted in Scientific Reports!

My paper with Marco Calzà, Francesco Gianesello, and Max Rinaldi (proudly 100% made within the Theoretical Gravitation and Cosmology Group led by myself and Max!) , where we study the stochastic gravitational wave background signal resulting from inspiraling cosmologically coupled BHs (see this earlier news item), has been accepted for publication in Scientific Reports, part of the Nature Portfolio collection of journals (therefore making this my third proper Nature publication)! With respect to the earlier version we have slightly changed the title and explained the content of Fig. 2 much more clearly, but the main message of the paper is otherwise unchanged. You can read the preprint version of the paper on arXiv: 2409.01801.

Stochastic gravitational wave background from cosmologically coupled black holes

Very happy to see my latest paper with Marco Calzà, Francesco Gianesello, and Max Rinaldi out! This is a 100% “made in Trentino” paper, and more precisely made within the Theoretical Gravitation and Cosmology Group led by myself and Max. At some point in 2023, the possibility that dark energy could be sourced by cosmologically coupled black holes (BHs), whose mass increases in time through purely cosmological growth even in the absence of accretion and merger events, received a lot of interest, especially given the possibility that signatures of such a coupling could have been observed in the growth of supermassive BHs in red-sequence elliptical galaxies. In today’s paper we show that mergers of such cosmologically coupled BHs would lead to a stochastic gravitational wave background whose strength is significantly larger (up to an order of magnitude stronger!) than the standard one from mergers of uncoupled BHs, with very interesting implications for the signal observed last year by pulsar timing arrays (among which NANOGrav, EPTA, PPTA, and CPTA), which is a bit too strong to be easily explainable by mergers of standard BHs. You can read our results in the preprint we just posted on arXiv: 2409.01801.