# No Run Gravity

## TL;DR

No Run Gravity is a cubic Horndeski theory that mimics general relativity's expansion history but exhibits distinct phenomenology, providing a counterexample to the idea that no modification implies standard gravity.

## Contribution

It introduces No Run Gravity, a novel cubic Horndeski model with specific properties, expanding the landscape of theories consistent with current observations.

## Key findings

- Calculates evolution of gravitational strength, sound speed, and cosmic growth.
- Projects sensitivities for upcoming DESI redshift space distortion data.
- Demonstrates rich phenomenology beyond simple $w(z)$ models.

## Abstract

Considering the dark energy/gravity landscape if next generation surveys of galaxies, cosmic microwave background radiation, and gravitational waves do not find clear modification of gravity, we develop No Run Gravity as a counterexample to the conclusion that this would imply general relativity with an expansion history described by an equation of state $w(z)$. No Run Gravity is a cubic Horndeski theory with a constant Planck mass, no gravitational slip, and no modification of gravitational waves, but a rich phenomenology beyond $w(z)$. We calculate the evolution of gravitational strength, sound speed, and cosmic growth within the theory and project sensitivities for upcoming DESI redshift space distortion data.