# Non-commutative effects on gravitational measurements

## TL;DR

This paper investigates how non-commutative geometries modify key gravitational tests like redshift, deflection, and time delay, providing bounds on non-commutative parameters using observational data.

## Contribution

It introduces calculations of gravitational effects in non-commutative inspired black holes and derives bounds on non-commutative parameters from observational data.

## Key findings

- Non-commutative effects alter gravitational predictions.
- Upper bounds on non-commutative parameters are established.
- Results differ from classical general relativity predictions.

## Abstract

The general theory of relativity is currently the accepted theory of gravity and as such, a large repository of test results has been obtained since its inception in 1915. However, in this paper we only focus on what are considered as the main tests but in non-commutative (NC) geometries. Using the coordinate coherent state formalism, we calculate the gravitational redshift, deflection, and time delay of light, separately, for NC inspired Schwarzschild and Riessner-Nordstrom black holes. We show the NC predictions have different behavior than the general relativity. We also provide an upper bound on the NC parameter by comparing the NC corrections with the accuracies of gravitational measurements in the case of typical primordial black holes produced in the early universe. In this regard, we use observational data for the scale factor $a$ at the end of inflation to obtain physical satisfactory results.