Question
Since the interaction term is proportional to this function in the Lieb–Liniger (“leeb LIN-ih-gher”) model of one-dimensional bosons (“BOZE-ons”), the particles only interact if they are in contact. For 10 points each:
[10e] Name this so-called “function” that is infinite at the origin and zero elsewhere.
ANSWER: Dirac delta function [or Dirac delta distribution]
[10h] This theoretical approach has been used to diagonalize the Lieb–Liniger Hamiltonian and a variety of other many-body systems, since a German-born physicist introduced it to solve the spin one-half XXX (“X-X-X”) model.
ANSWER: Bethe ansatz (“BAY-tuh ON-zotz”)
[10m] For weak interactions, this function for the Lieb–Liniger model has a branch that is equivalent to this function as derived for superfluids by Nikolay Bogoliubov. For phonons, the two branches of this function correspond to optical and acoustic modes.
ANSWER: dispersion relation [or dispersion curve; or energy spectrum; prompt on spectrum]
<Physics>
Summary
| 2023 ACF Nationals | 04/22/2023 | Y | 1 | 10.00 | 100% | 0% | 0% |
Data
| Georgia Tech A | Chicago A | 10 | 0 | 0 | 10 |