This scientist names a model that was initially developed by Landau to explain the behavior of liquid helium-3 and that breaks down in the one-dimensional case, where a model named for Luttinger must be used instead. A construct named for this scientist can be mapped using periodic oscillations in magnetic susceptibility in the De Haas–Van Alphen effect, or by measuring the energy and emission angle of photoelectrons in ARPES. That surface named for this scientist separates occupied and unoccupied (10[1])states in reciprocal space. This scientist names a quantity whose location within a material’s electronic band structure determines if it is a conductor, semiconductor, or insulator. For 10 points, what Italian physicist’s namesake level equals the amount of work required to add an electron to a system? ■END■ (10[2])