Is There Only One Vacuum?

TL;DR

This paper reexamines the foundations of quantum field theory, proposing a new framework that questions the uniqueness of the vacuum state and explores implications for different spacetime geometries.

Contribution

It introduces a novel QFT scattering framework separating path integrals and Hilbert spaces, and critically analyzes the concept of a unique vacuum and its role in various spacetime contexts.

Findings

Proposes a new QFT scattering framework separating interaction kernels and asymptotic states.

Questions the assumption of a unique vacuum in QFT.

Reevaluates vacuum energy cancellation schemes and applicability to non-flat spacetimes.

Abstract

This work proposes a reconstruction of the quantum field theory (QFT) scattering framework: the path integral governs an interaction kernel region, while the Hilbert space encodes asymptotic free boundary conditions. We critically reexamine foundational assumptions and standard observables of QFT, raising the possibility of a unique vacuum. We also introduce a new thermodynamic perspective on vacuum loop contributions. The motivation behind certain vacuum energy cancellation schemes is reconsidered, and the applicability of QFT to spacetimes without asymptotic flatness, such as de Sitter (dS) space, is questioned at a fundamental level.