# Constraints of general screened modified gravities from comprehensive analysis of binary pulsars

## TL;DR

This paper analyzes how screened modified gravity theories affect binary pulsar dynamics, using observational data to constrain deviations from general relativity and confirming GR's predictions within current limits.

## Contribution

It provides a detailed calculation of post-Keplerian parameters in screened modified gravity and uses pulsar data to set new bounds on scalar charges and deviations from GR.

## Key findings

- Dipole radiation constrains scalar charges more tightly in NS-WD binaries.
- PSR B1913+16 and PSR J1738+0333 provide the strongest constraints.
- Results are consistent with general relativity, excluding significant deviations.

## Abstract

Testing gravity by binary pulsars nowadays becomes a key issue. Screened modified gravity is a kind of scalar-tensor theory with screening mechanism in order to satisfy the tight Solar System tests. In this paper, we investigate how the screening mechanism affects the orbital dynamics of binary pulsars, and calculate in detail the five post-Keplerian (PK) parameters in this theory. These parameters differ from those of general relativity (GR), and the differences are quantified by the scalar charges, which lead to the dipole radiation in this theory. We combine the observables of PK parameters for the ten binary pulsars, respectively, to place the constraints on the scalar charges and possible deviations from GR. The dipole radiation in the neutron star (NS) - white dwarf (WD) binaries leads to more stringent constraints on deviations from GR. The most constraining systems for the scalar charges of NS and WD are PSR~B1913$+$16 and PSR~J1738$+$0333, respectively. The results of all tests exclude significant strong-field deviations and show good agreement with GR.