Quasinormal modes of black holes in f(T) gravity

We calculate the quasinormal modes (QNM) frequencies of a test masslessscalar field and an electromagnetic field around static black holes in $f(T)$gravity. Focusing on quadratic $f(T)$ modifications, which is a goodapproximation for every realistic $f(T)$ theory, we first extract thespherically symmetric solutions using the perturbative method, imposing twoans$\ddot{\text{a}}$tze for the metric functions, which suitably quantify thedeviation from the Schwarzschild solution. Moreover, we extract the effectivepotential, and then calculate the QNM frequency of the obtained solutions.Firstly, we numerically solve the Schr$\ddot{\text{o}}$dinger-like equationusing the discretization method, and we extract the frequency and the timeevolution of the dominant mode applying the function fit method. Secondly, weperform a semi-analytical calculation by applying the WKB method with the Padeapproximation. We show that the results for $f(T)$ gravity are differentcompared to General Relativity, and in particular we obtain a different slopeand period of the field decay behavior for different model parameter values.Hence, under the light of gravitational-wave observations of increasingaccuracy from binary systems, the whole analysis could be used as an additionaltool to test General Relativity and examine whether torsional gravitationalmodifications are possible.