Modelling pulsar gamma-ray light curves using a geometric current sheet model

The publication of the Third Pulsar Catalog (3PC) by the Fermi Large Area Telescope (LAT) team marked a significant milestone for high-energy pulsar science. In it, the light curves and spectra of nearly 300 pulsars are presented, along with some interesting correlations between timing and spectral parameters. This wealth of data provides impetus for continued development of pulsar emission models. Over the years, numerous models have been developed, focusing on different physical aspects or regimes (e.g., global current flow and magnetic field structure, pair creation microphysics, or emission and beaming), and with different outputs (e.g., multi-frequency light curves, multi-component spectra, or single-band pulse shapes only). Magnetohydrodynamic (MHD) and particle-in-cell (PIC) models each have their respective strengths but are often computationally expensive for a suitable coverage of the parameter space. Machine learning has recently been invoked to speed up the process. An alternative, interim step that we are exploring is to implement a geometric current sheet (CS) model, akin to the traditional outer gap and two-pole caustic models, but with emission occurring beyond the light cylinder (the magnetospheric boundary where the co-rotation speed equals that of light in vacuum). We present first results and insights gained by evaluating the beamed output (phase plots or sky maps that present beamed emission across the sky) from this model, as well as from contrasting example predicted light curves for the Vela pulsar using the various geometric models. The latter results also feature predictions from a geometric radio conal model.