### Peter Arnold

*Ph.D., 1986, Stanford*

*Professor*

**Associate Chair**

*Theoretical High Energy Physics*

#### Research Interests

Prof. Arnold studies the theory of the strong, weak, and electromagnetic interactions at extremely high, relativistic temperatures, such as in the very early Universe (less than a millionth of a second after the Big Bang) or in relativistic collisions in heavy ion accelerators. Topics he has studied include investigating why there is significantly more matter than anti-matter in the Universe and understanding the properties of quark-gluon plasmas. The theoretical methods used for these very high energy problems (as much as a quadrillion degrees Kelvin) can also be applied to certain problems at very low temperatures (less than a millionth of a degree above absolute zero), and Prof. Arnold has also made some detours from his usual work on particle theory to study the transition temperature for Bose-Einstein condensation of dilute gases of extremely cold atoms.

For lay descriptions of some of Prof. Arnold’s research, click here (quark-gluon plasmas) and here (older work on the problem of matter/anti-matter asymmetry). For Prof. Arnold’s HEP-related publications, click here.

#### Selected Publications

P. Arnold, S. Iqbal, and T. Rase, "Strong- vs. weak-coupling pictures of jet quenching: a dry run using QED," [arXiv.org:1810.06578]

P. Arnold and S. Iqbal, "The LPM effect in sequential bremsstrahlung," JHEP **04** (2015) 070 [arXiv.org:1501.04964]

P. Arnold, P. Szepietwoski, D. Vaman, and G. Wong, "Tidal stretching of gravitons into classical strings: application to jet quenching with AdS/CFT,” JHEP **02** (2013) 130 [arXiv.org: 1212.3321]

P. Arnold, C. Dogan, and G. Moore, “The bulk viscosity of high-temperature QCD,” Phys. Rev. **D74** (2006) 085021 [arXiv.org: hep-ph/0608012]

P. Arnold and G. Moore, "Transition temperature of a dilute homogeneous imperfect Bose gas," Phys. Rev. Lett. 87 (2001) 120401 [arXiv.org: cond-mat/0103228]

P. Arnold and L. McLerran, "Sphalerons, small fluctuations and baryon number violation in electroweak theory," Phys. Rev. **D36** (1987) 581.

#### News Items

#### Honors

**APS Fellow**[2014]

For accomplishments in developing gauge theories at high temperature.