May 13th 2026, @IEM-CSIC

C/Serrano 121, 28006. Madrid

Conference Room

11:15h     Welcome coffee

11:30h     First Talk

Speaker: Bruce Allen (AEI Hannover)

Title: Have pulsar timing arrays  detected nano-Hz gravitatonal waves?

Abstract: Pulsar timing arrays (PTA) seek to detect nano-Hz frequency gravitational waves by observing their effects on the arrival times of pulses from radio pulsars.  In June 2023, five different PTA collaborations published papers based on up to two decades of observations.  Some reported no evidence that they had seen the effects of nano-Hz gravitational waves.  Others reported "compelling evidence". At the same time, all of the PTAs (apart from the Chinese PTA) released their full data set. Here, we report on the first combined analysis of that full public data set. Because this independent analysis increases both the number of pulsars observed and the number of data samples per pulsar, it significantly increases the GW strain sensitivity and the detection confidence.  Our paper on this topic arXiv:2512.08666 is currently under review.

15:00h     Second Talk

Speaker: Alicia M. Sintes Olives (U. Illes Balears & IEEC)

Title: The First Decade of Ground-Based Gravitational-Wave Astronomy

Abstract: The first direct detection of gravitational waves on September 14, 2015 marked the beginning of gravitational-wave astronomy. On November 18, 2025, the LIGO–Virgo–KAGRA (LVK) collaboration completed its fourth observing run, concluding a decade of observations with a global network of ground-based detectors. In this talk, I will review the main results obtained by the LVK collaboration over this period. These include the growing catalog of compact binary coalescences, comprising binary black hole and neutron star mergers, and their implications for astrophysics, fundamental physics, and cosmology. I will summarize key findings from successive observing runs, improvements in detector sensitivity and network performance, and the role of multi-messenger observations. These results demonstrate the transition of gravitational-wave astronomy from initial detections to a mature observational field with increasing statistical power and precision, setting the stage for future discoveries.