Packet 4: Bonus 14
Fluctuations in this entity occur from the production of virtual electron–positron pairs, which explains the Casimir effect. For 10 points each:
[10e] Name this entity whose namesake polarization occurs in quantum electrodynamics due to virtual photons.
ANSWER: vacuum
[10h] Vacuum polarization contributes an extremely small but nonzero term in the formula of this quantity, which modifies a classical potential. This quantity is the first-order contribution to the Lamb shift.
ANSWER: Uehling potential
[10m] This physicist’s namesake limit occurs when fields become nonlinear due to vacuum polarization. This physicist, whose differential approach to QFT contrasts with Feynman’s path integral formulation, names a scattering equation with Lippmann.
ANSWER: Julian Schwinger [or Julian Seymour Schwinger]
<Harvard, Physics> | D. Prelims 4 - Toronto B + Harvard + Michigan + Minnesota
| Heard | PPB | E % | M % | H % |
|---|---|---|---|---|
| 21 | 9.52 | 67% | 24% | 5% |
Conversion
| Team | Opponent | Part 1 | Part 2 | Part 3 | Total | Parts |
|---|---|---|---|---|---|---|
| Brown | Johns Hopkins | 10 | 0 | 10 | 20 | EM |
| Bruin | Chicago B | 0 | 0 | 0 | 0 | |
| Columbia A | British Columbia | 10 | 0 | 0 | 10 | E |
| Cornell | Maryland A | 10 | 0 | 0 | 10 | E |
| Georgia Tech A | Swarthmore | 10 | 0 | 0 | 10 | E |
| Georgia Tech C | Illinois B | 0 | 0 | 10 | 10 | M |
| MIT | Waterloo | 10 | 10 | 0 | 20 | EH |
| NYU B | Columbia B | 0 | 0 | 0 | 0 | |
| Northwestern A | Stanford A | 10 | 0 | 0 | 10 | E |
| Northwestern B | Illinois A | 0 | 0 | 0 | 0 | |
| Ohio State | Georgetown | 10 | 0 | 10 | 20 | EM |
| Penn State | Georgia Tech B | 0 | 0 | 0 | 0 | |
| Pittsburgh | Indiana | 10 | 0 | 0 | 10 | E |
| Rutgers | Virginia | 10 | 0 | 0 | 10 | E |
| Stanford B | UC Berkeley B | 0 | 0 | 0 | 0 | |
| Texas | WashU | 10 | 0 | 0 | 10 | E |
| UC Berkeley A | North Carolina | 10 | 0 | 10 | 20 | EM |
| UCF | Cambridge | 10 | 0 | 0 | 10 | E |
| UCLA | Toronto A | 10 | 0 | 10 | 20 | EM |
| Vanderbilt | NYU A | 10 | 0 | 0 | 10 | E |
| Virginia Tech | Maryland B | 0 | 0 | 0 | 0 |
Summary
| Tournament | Edition | Match | Heard | PPB | E % | M % | H % |
|---|---|---|---|---|---|---|---|
| Main Site | 2026-04-17 | ✓ | 21 | 9.52 | 67% | 24% | 5% |