How Well Do You Know the Weinberg-Witten Theorem? Quiz

The Weinberg-Witten theorem states that massless particles (either composite or elementary) with spin j > 1/2 cannot carry a Lorentz-covariant current, while massless particles with spin j > 1 cannot carry a Lorentz-covariant stress-energy. This theorem is usually interpreted to mean that the graviton (j = 2) cannot be a composite particle in a relativistic quantum field theory. This theorem has significant implications for theories of quantum gravity, which seek to reconcile quantum mechanics with general relativity. It places constraints on the types of particles that can exist in a quantum field theory, and it has been used to argue against certain models of quantum gravity.

The Weinberg-Witten theorem was independently formulated and proved by Steven Weinberg and Edward Witten, two prominent physicists. Steven Weinberg was awarded the Nobel Prize in Physics in 1979 for his contributions to the unification of the weak force and electromagnetic interaction. Edward Witten is known for his research in string theory and was awarded the Fields Medal in 1990.

The Weinberg-Witten theorem relies on the principle of the absence of certain continuous symmetries in quantum field theories. The theorem establishes constraints on the possible continuous global symmetries, addressing the potential presence of massless Goldstone bosons associated with these symmetries.

String theory is in agreement with the Weinberg-Witten theorem because it packages creation/annihilation operators in the string. This allows string theory to avoid the restrictions imposed by the theorem. The theorem states that massless particles (either composite or elementary) with spin greater than 1/2 cannot carry a Lorentz-covariant current, while massless particles with spin greater than 1 cannot carry a Lorentz-covariant stress energy.

The Weinberg-Witten theorem, proposed by Steven Weinberg and Edward Witten, was published in 1983. In their paper titled "Limits on Massless Particles," the authors presented the theorem, which addresses the potential continuous symmetries in quantum field theories. The theorem specifically focuses on the absence of certain continuous global symmetries that would lead to massless Goldstone bosons.

This theorem places constraints on the properties of massless particles, outlining limitations on their potential symmetries. The constraints provide insights into the nature and behavior of massless particles within the context of quantum field theories.

The Weinberg-Witten theorem implies that massless particles, subject to its constraints, cannot possess spin greater than 1/2. This restriction on spin is a crucial aspect of the theorem and influences the characteristics of massless particles in theoretical physics.

The Weinberg-Witten theorem is primarily a result within the framework of quantum field theory, a branch of physics that describes the behavior of fields and particles at the quantum level.

The theorem states that massless particles (either composite or elementary) with spin greater than 1/2 cannot carry a Lorentz-covariant current, while massless particles with spin greater than 1 cannot carry a Lorentz-covariant stress-energy. This is usually interpreted to mean that the graviton (a hypothetical elementary particle that mediates the force of gravity) cannot be a composite particle in a relativistic quantum field theory.

The Weinberg-Witten theorem imposes limitations on the existence of massless Goldstone bosons, which are particles associated with spontaneous symmetry breaking. The theorem's constraints restrict the presence of these bosons, influencing the dynamics of symmetries in quantum field theories.