First-passage processes are pervasive in the world around us, yet a general framework for understanding their response to external perturbations remains elusive. In this talk, I will present a universal linear response theory for first-passage times, showing that the response of the mean first-passage time to a rare perturbation depends only on the unperturbed mean and variance, and the mean completion time after perturbation onset. I will demonstrate how this simple, yet powerful, result offers a tool for predicting the impact of perturbations on first-passage processes across various scenarios, including non-trivial ones such neural network training. I will also demonstrate how the result can be used in reverse to infer fluctuations from mean first-passage times, opening the door for the extraction of single-molecule fluctuations from bulk (concentration) measurements.FOR THE LATEST UPDATES AND CONTENT ON SOFT MATTER AND BIOLOGICAL PHYSICS AT THE WEIZMANN, VISIT OUR WEBSITE: https://www.bio
