#### IMSc Webinar

#### Dynamical effects in the second derivative of spin and orbital frequency of radio pulsars

#### Dhruv Pathak

##### IMSc

*Precision timing analysis of radio pulsars gives many interesting results and is expected to contribute further in many areas of fundamental physics in the future. In this connection, it is important to understand the external factors affecting the values of parameters estimated in the timing analysis. Among all these timing parameters, the measured values of the frequency derivatives are affected by the velocity and acceleration of the pulsars. These effects are known as ‘dynamical contributions’. In this talk, I will talk about the formalism for deriving the analytical expressions for such dynamical contributions in the second derivative of frequency (spin or orbital) of pulsars in terms of the Galactic coordinates, the proper motion, the pulsar distance, the radial velocity, and observed values of frequency and its derivatives. I will compare these effects on the pulsars in the Galactic field with those near the Galactic Centre. I will also talk about the effects of these dynamical terms on the parameters like braking index as well as the orbital frequency second derivative.*

Done