Bell violation in the Sky

TL;DR

This paper explores the theoretical possibility of observing Bell inequality violations in a cosmological setting, proposing a model-independent framework involving massive particle creation and correlation functions to test quantum mechanics principles on a cosmic scale.

Contribution

It introduces a novel cosmological Bell test framework using scalar fluctuations and time-dependent masses, including a new parameter and bounds on particle masses, independent of inflationary model assumptions.

Findings

Derived expressions for one-point and two-point correlation functions.

Proposed a new cosmological parameter related to inflationary observables.

Established bounds on heavy particle masses from the Bell violation setup.

Abstract

In this work, we have studied the possibility of setting up Bell's inequality violating experiment in the context of cosmology, based on the basic principles of quantum mechanics. First we start with the physical motivation of implementing the Bell's inequality violation in the context of cosmology. Then to set up the cosmological Bell violating test experiment we introduce a model independent theoretical framework using which we have studied the creation of new massive particles by implementing the WKB approximation method for the scalar fluctuations in presence of additional time dependent mass contribution. Next using the background scalar fluctuation in presence of new time dependent mass contribution, we explicitly compute the expression for the one point and two point correlation functions. Furthermore, using the results for one point function we introduce a new theoretical cosmological parameter which can be expressed in terms of the other known inflationary observables and can also be treated as a future theoretical probe to break the degeneracy amongst various models of inflation. Additionally, we also fix the scale of inflation in a model independent way without any prior knowledge of primordial gravitational waves. Next, we also comment on the technicalities of measurements from isospin breaking interactions and the future prospects of newly introduced massive particles in cosmological Bell violating test experiment. Further, we cite a precise example of this set up applicable in the context of string theory motivated axion monodromy model. Then we comment on the explicit role of decoherence effect and high spin on cosmological Bell violating test experiment. In fine, we provide a theoretical bound on the heavy particle mass parameter for scalar fields, graviton and other high spin fields from our proposed setup.