space Practical Magic

Scientists are using a network of spinning stars to create a telescope the size of a galaxy to solve the universe's biggest mysteries.

March 13, 2026

Original Paper

The Targeted Standard Siren Cosmology with Pulsar Timing Arrays

Shubhit Sardana, Boris Goncharov, Jacob Cardinal Tremblay

arXiv · 2603.12168

The Takeaway

There is a major conflict in physics called the 'Hubble tension' regarding how fast the universe is expanding. By precisely timing the pulses of dead stars (pulsars) across the sky, astronomers believe they can create a 'standard siren' accurate enough to finally settle the debate.

From the abstract

The sky localisation of about $10$ to $100~\text{deg}^2$, which is expected to be achieved in all-sky blind searches for gravitational waves from supermassive black hole binaries (SMBHBs) with Pulsar Timing Array (PTA) experiments, has long been posed as a prohibitive factor in utilising these sources as standard sirens for precision cosmology. We propose a solution to this problem, which makes use of targeted searches rather than all-sky blind searches for SMBHBs. Using our simulated data infor