Ramamurti Shankar organized the low-energy physics of interacting fermions using the renormalization group. The construction retains momentum modes in a thin region around the Fermi surface, integrates out part of that region, and asks how the remaining interactions change as the energy scale decreases. Classifying the interactions as relevant, irrelevant or marginal explains why many microscopic details disappear from low-energy predictions, while selected channels can grow and destabilize the starting description.[ref]
Renormalization Group Approach to Interacting Fermions by Ramamurti Shankar. Abstract and introduction, cutoff around the Fermi surface and classification of perturbations
A physicist.[ref]
https://physics.yale.edu/profile/ramamurti-shankar. Independent professional profile
Portrait of Ramamurti Shankar
. AllenTalk. CC BY 3.0, via Wikimedia Commons. Source. Articles by others on the same topic
Ramamurti Shankar is a renowned physicist, primarily known for his contributions to theoretical physics and his work in education. He is a professor at Yale University, where he has made significant contributions to the fields of quantum mechanics and other areas of physics. In addition to his research, Shankar is well recognized for his ability to teach complex concepts in an accessible manner, which is exemplified through his popular textbooks on quantum mechanics and other topics.