# The Modern Physics of Compact Stars and Relativistic Gravity 2015

30 September 2015 to 3 October 2015
Yerevan, Armenia
Etc/GMT+4 timezone

## Piercing the Vainshtein screen: local constraints on modified gravity

2 Oct 2015, 14:00
40m
Small Hall, Guesthouse ()

### Speaker

Dr Hermano Velten (Centre de Physique Théorique UMR 7332)

### Description

By using observations of the Hulse-Taylor pulsar we constrain the gravitational wave (GW) speed to the level of $10^{-2}$. We apply this result to scalar-tensor theories that generalize Galileon 4 and 5 models, which display anomalous propagation speed and coupling to matter for GWs. We argue that this effect survives conventional screening due to the persistence of a scalar field gradient inside virialized overdensities, which effectively “pierce” the Vainshtein screening. In specific branches of solutions, our result allows to directly constrain the cosmological couplings in the effective field theory of dark energy formalism.

### Primary author

Dr Hermano Velten (Centre de Physique Théorique UMR 7332)

### Presentation Materials

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