Why the Energy Density is Positive

Wednesday, March 8, 2017 - 3:30pm

A physical system is stable if its Hamiltonian is bounded below, so that we can define a positive notion of "energy" relative to the ground state.  But what about the local energy density---can that be negative?  I will provide an elegant derivation that a positive energy density always exists, in (discrete or continuous) classical systems with one spatial dimension.  When we try to apply the same argument to quantum systems, we will obtain a surprising result linking the energy to information theory.

3 Le Conte
Dr. Aron Wall
Institute for Advanced Study (Princeton)