Thermodynamics via Creation from Nothing: Limiting the Cosmological Constant Landscape

TL;DR

This paper proposes a quantum cosmological model where the universe's creation is described by a density matrix, limiting the cosmological constant to a specific bounded range influenced by quantum effects and particle physics.

Contribution

It introduces a novel quantum framework that constrains the cosmological constant range using density matrices and instanton solutions, linking quantum effects to string landscape selection.

Findings

The cosmological constant is bounded between $ ext{Lambda}_{ ext{min}}$ and $ ext{Lambda}_{ ext{max}}$.

Quantum effects and conformal anomalies determine the cutoff scales.

A potential dynamical mechanism for string vacuum selection is suggested.

Abstract

The creation of a quantum Universe is described by a {\em density matrix} which yields an ensemble of universes with the cosmological constant limited to a bounded range $\Lambda_{\rm min}\leq \Lambda \leq \Lambda_{\rm max}$. The domain $\Lambda<\Lambda_{\rm min}$ is ruled out by a cosmological bootstrap requirement (the self-consistent back reaction of hot matter). The upper cutoff results from the quantum effects of vacuum energy and the conformal anomaly mediated by a special ghost-avoidance renormalization. The cutoff $\Lambda_{\rm max}$ establishes a new quantum scale -- the accumulation point of an infinite sequence of garland-type instantons. The dependence of the cosmological constant range on particle phenomenology suggests a possible dynamical selection mechanism for the landscape of string vacua.