Standard constraints on the shadow radius of black holes in $d$-dimensional space-time: The case of regular Einstein-Gauss-Bonnet solutions

Abstract

In this work, we propose a $d$-dimensional constraint formula for the black hole shadow radius, providing a standardized framework for using observational confidence intervals to constrain the corresponding characteristic parameters in $d$-dimensional black hole solutions. This approach can correct the misapplication of shadow radius constraints in some previous studies. Subsequently, we selected two regular Einstein-Gauss-Bonnet (EGB) black hole solutions as a representative example to test the $d$-dimensional shadow constraint formula. Our analysis reveals that the characteristic parameters within these $d$-dimensional black hole solutions maintain physically meaningful bounded domains under shadow radius constraints. We further propose that this $d$-dimensional shadow constraint formula is universal and can be applied to constrain the characteristic parameters in other high-dimensional spherically symmetric black hole solutions.