Kappa vacua: Infinite number of new vacua in two-dimensional quantum field theory

TL;DR

This paper introduces an infinite family of vacua in two-dimensional quantum field theory, generalizing known vacua and revealing a continuous spectrum of possible ground states parameterized by a positive real number.

Contribution

It proposes a new mode classification in quantum field theory, extending the concept of vacua beyond Minkowski and Rindler cases using a parameterized mode.

Findings

Identifies an infinite set of vacua labeled by a parameter κ.

Shows Minkowski and Rindler vacua are special cases of the κ-vacuum.

Introduces a generalized mode extending the Unruh-Minkowski mode.

Abstract

We uncover an infinite number of vacua in two-dimensional quantum field theory, the Klein-Gordon field for simplicity, by conceiving a new mode that is classified by a real positive parameter $\kappa$. We show each mode has a distinct vacuum, say $\kappa$-vacuum. This new mode is a generalization of the Unruh-Minkowski mode. Moreover, the Minkowski and Rindler vacua are special cases of the $\kappa$-vacuum for $\kappa = 1$ and $\kappa \rightarrow \infty$, respectively.