Erick J. Weinberg (born August 29, 1947) is a theoretical physicist and professor of physics at Columbia University. Weinberg received his undergraduate degree from Manhattan College in 1968. He obtained his Ph.D. from Harvard University in 1973 under the supervision of Sidney Coleman, with whom he discovered the Coleman–Weinberg mechanism for spontaneous symmetry breaking in quantum field theory. Weinberg works on various branches in high-energy theory, including black holes, vortices, Chern–Simons theory, magnetic monopoles in gauge theories and cosmic inflation. He also serves as the Editor of Physical Review D, as well as a visiting scholar of the Korea Institute for Advanced Study (KIAS). Academic career After receiving his doctorate, Weinberg went to the Institute for Advanced Study in Princeton, New Jersey as a postdoctoral researcher. In 1975, he became an assistant professor of physics at Columbia University. He was promoted to full professor in 1987. From 2002 to 2006, Weinberg served as the chair of Columbia University's physics department. Weinberg is still actively researching BPS monopoles and vacuum decay. Notable works Weinberg has worked on various branches in theoretical high energy physics, including the theory of spontaneous symmetry breaking, inflation, the theory of supersymmetric solitons, and the theory of vacuum decay via the nucleation of quantum/thermal bubbles. Coleman–Weinberg potential Spontaneous symmetry breaking occurs in a theory when the state with the lowest energy does not have as many symmetries as the theory itself, therefore one sees degenerate vacua connected by the quotient between the symmetry of the theory and the symmetry of the state, and the particle spectrum is classified by the symmetry group of the lowest energy state (vacuum). In the case that the quotient can be parametrized by the continuous parameter(s), the local fluctuations of these parameters can be regarded as bosonic excitations (if the symmetry is bosonic), usually called Goldstone boson, which has profound implications. When coupled to gauge fields, these bosons mix into the longitudinal polarizations of the gauge fields and give masses to the fields, this is how Higgs mechanism works. Usually, the way to realize spontaneous symmetry breaking is to introduce a scalar field that has a tachyonic mass parameter, classically, then the classical vacuum is the solution that stays at the bottom of the potential, with the leading quantum contribution from the uncertainty principle, the vacuum can be viewed as a Gaussian wave packet around the lowest point of the potential. The