# Stress testing the dark energy equation of state imprint on supernova data

## TL;DR

This study assesses how well standard supernova analyses can detect deviations from a cosmological constant in dark energy's equation of state, revealing limited sensitivity to complex redshift dependencies.

## Contribution

Introduces a novel random curve generator for w(z) and evaluates the detectability of dark energy deviations using mock supernova data and Bayesian analysis.

## Key findings

- Standard supernova analysis has limited sensitivity to complex w(z) variations.
- Larger deviations in w(z) do not always produce easily detectable signals.
- Physics beyond the standard model may be hidden in plain sight.

## Abstract

This work determines the degree to which a standard Lambda-CDM analysis based on type Ia supernovae can identify deviations from a cosmological constant in the form of a redshift-dependent dark energy equation of state w(z). We introduce and apply a novel random curve generator to simulate instances of w(z) from constraint families with increasing distinction from a cosmological constant. After producing a series of mock catalogs of binned type Ia supernovae corresponding to each w(z) curve, we perform a standard Lambda-CDM analysis to estimate the corresponding posterior densities of the absolute magnitude of type Ia supernovae, the present-day matter density, and the equation of state parameter. Using the Kullback-Leibler divergence between posterior densities as a difference measure, we demonstrate that a standard type Ia supernova cosmology analysis has limited sensitivity to extensive redshift dependencies of the dark energy equation of state. In addition, we report that larger redshift-dependent departures from a cosmological constant do not necessarily manifest easier-detectable incompatibilities with the Lambda-CDM model. Our results suggest that physics beyond the standard model may simply be hidden in plain sight.