We found "ghosts" of impossibly heavy particles from the start of time hidden in the echoes of the Big Bang.
arXiv · March 18, 2026 · 2603.15728
The Takeaway
The extreme energy of the Big Bang acted like a giant particle accelerator, creating massive states thousands of times heavier than anything we can produce in labs today. By re-analyzing satellite data, physicists found evidence that these giant particles left a permanent fingerprint on the structure of the cosmos.
From the abstract
Searches for primordial non-Gaussianity (NG) has the potential to not only reveal the physics of cosmic inflation, but also the structure of fundamental interactions at the highest energies. The cosmological collider (CC) physics program exemplifies this possibility and demonstrates how searches for oscillatory NG can lead to mass-spin spectroscopy of extremely heavy states. Adopting an effective field theory approach, we find the class of Feynman diagrams that can give the largest NG mediated b