Wigner's little groups define internal space-time symmetries of Elementary Particles.

Weinberg asking talking to Wigner in 1957 when he was a student at Princeton (1957).

• Steven Weinberg
  Phys. Rev. 133, B1318 (1964).
  

• Steven Weinberg
  Phys. Rev. 134, B882 (1964).
  

• Steven Weinberg
  Phys. Rev. 135, B1049 (1964).

Weinberg was interested in finding a representation of Wigner's little group suitable for massless particles. Click here for a brief history of this subject.

Was Weinberg Wigner's student at Princeton? Was my advisor Wigner? The answer is No to both questions. See next slide.