Constraining spacetime deformation based on astrophysical observations from radio pulsars
Abstract
Abstract The present work is devoted to investigations of cut-off for plasma magnetospheric radiations around magnetized neutron stars in the presence of spacetime deformation. In this way, we first analysed behaviour deathline conditions of curvature radiations (CR), and inverse Compton scattering (ICS) around deformed neutron stars. Through the analyses, we have obtained upper limits for the deformation parameter which causes switchingof pulsars in radio to $$\gamma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> -rays bands of the electromagnetic spectrum. It is observed that the upper limits for the radio waves and $$\gamma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> -rays cut off are not the same, but they are different, the limit is higher for radio wave cut off than $$\gamma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> -rays. Moreover, our detailed analyses show that this limit also depends on the period of pulses from pulsars and its delay (period derivation). Finally, we have obtained upper limits for the deformation parameter for selected several millisecond pulsars using the deathline conditions.