Spin in Relativistic Quantum Theory

Relativistic Quantum Theory with Fractional Spin and Statistics

Relativistic Quantum Field Theory

Relativistic Spin Networks and Quantum Gravity

Relativistic spin networks are de ned by considering the spin covering of the group SO(4), SU(2) SU(2). Relativistic quantum spins are related to the geometry of the 2-dimensional faces of a 4-simplex. This extends the idea of Ponzano and Regge that SU(2) spins are related to the geometry of the edges of a 3-simplex. This leads us to suggest that there may be a 4-dimensional state sum model for...

Spin in Quantum Field Theory

I introduce spin in field theory by emphasizing the close connection between quantum field theory and quantum mechanics. First, I show that the spin–statistics connection can be derived in quantum mechanics without relativity or field theory. Then, I discuss path integrals for spin without using spinors. Finally, I show how spin can be quantized in a path–integral approach, without introducing ...

Quasiparticle excitations in relativistic quantum field theory

We analyze the particle-like excitations arising in relativistic field theories in states different than the vacuum. The basic properties characterizing the quasiparticle propagation are studied using two different complementary methods. First we introduce a frequency-based approach, wherein the quasiparticle properties are deduced from the spectral analysis of the twopoint propagators. Second,...