The emergence of the three-dimensional structure of the cosmic web over
the history of the Universe displays very distinctive features when
observed in X-rays, where both the most massive collapsed structure
(clusters of galaxies) and the most energetic events in the life of
galaxies (AGN and Quasars) reveal themselves unambiguously. The next
generation of wide-area, sensitive X-ray surveys designed to map the hot
and energetic Universe will be heralded by eROSITA (extended ROentgen
Survey with an Imaging Telescope Array), the core instrument on the

We are organising a cycle of seminars of philosophy of science at APC.
During 30 min, philosophers will present their research on a topic related to the themes of research of the laboratory. The presentation will be folllowed by a 30-min discussion between the audience and the speaker.
The event is open to all APC members, external members can attend on request.
A zoom link is communicated by email for the ones who wish to attend remotely.

First order cosmological phase transitions in beyond the Standard Model theories may trigger the

Primordial black holes are a dark matter candidate, which may originate from strong perturbations created during inflation. These perturbations can be studied using the formalism of stochastic inflation. I present a numerical approach to this problem, where the stochastic dynamics is solved by generating a large number of random realizations. This makes it possible to go beyond analytical approximations and take into account additional effects such as backreaction between the perturbations and the background.

Pulsar Timing Arrays (PTAs) aim to detect nHz gravitational waves (GWs) from supermassive black hole binaries (SMBHBs). This is done by looking for correlated variations of the Time of Arrivals (TOA) across an array of ultra-stable millisecond pulsars. Comparing the predicted TOAs from our timing model against the measured TOAs gives us the residuals. These contain the imprint of GWs, but also other effects and sources of noise processes.

There are two possible approaches to describe a population of astrophysical gravitational wave (GW) sources: one can focus on high signal-to-noise sources that can be detected individually, and build a catalogue.

Although inflation is broadly accepted to be the standard paradigm for early universe cosmology, many of its quantum properties remain unknown. For instance, the crowning glory of inflation lies in explaining late-time macroscopic inhomogeneities as arising from tiny quantum fluctuations; however, most of the established literature ignores the crucial role that entanglement between the modes of the fluctuating field plays in its observable predictions.