The butterfly effect is a metaphor for the extreme sensitivity of nonlinear chaotic systems found generically when there is more than 1-degree of freedom, examples abound from the gravitational three-body problem to the weather. Chaos and quantum physics have had an uneasy relationship which has implications in explorations of the no-man's land of classical-quantum boundaries and goes to the heart of the foundations of statistical physics. The talk will introduce surprising connections of classical chaos to quantum entanglement and implications therein to many-body localization and thermalization of isolated systems. Recent proposals of measuring quantum chaos, such out-of-time-ordered correlators (OTOC) and scrambling will be discussed briefly as they bring us to the latest avatar of the butterfly effect which seems to
have reached black holes, now conjectured to be nature's most chaotic and fastest scramblers.
About the speaker: Arul graduated as a Mechanical Engineer in 1988 from IIT Madras, attending classes mostly in the MSB during breaks from the CRD canteen. He managed to get a Ph. D. from the State University of New York at Stony Brook in theoretical physics in 1993, after which he was a post-doc and later faculty at the Physical Research Laboratory at Ahmedabad till 2003. During this time he also started studying the connections between chaos and quantum entanglement, a fringe activity at that time. The Indian National Science Academy, in an obvious and momentary lapse of judgement, gave him the Young Scientist award in 1998. Since 2003 he has been a faculty at IITM. He has foisted himself as a long-term visiting scientist or faculty on Washington State University at Pullman, IIT Kanpur, and the Max Planck Institute for the Physics of Complex Systems, at Dresden Germany, which he still periodically haunts. He evinces keen interest in quantum chaos, quantum information, random matrix theory (he is proud to have found that multiplying random matrices increases their probability to have real eigenvalues, but nobody really cares) and quantum many-body systems, but still struggles with problems in classical mechanics.