  We discuss the effect of Beyond the Standard Model charged current
interactions on the detection of the Cosmic Neutrino Background by neutrino
capture on tritium in a PTOLEMY-like detector. We show that the total capture
rate can be substantially modified for Dirac neutrinos if scalar or tensor
right-chiral currents, with strength consistent with current experimental
bounds, are at play. We find that the total capture rate for Dirac neutrinos,
$\Gamma_{\rm D}^{\rm BSM}$, can be between 0.3 to 2.2 of what is expected for
Dirac neutrinos in the Standard Model, $\Gamma_{\rm D}^{\rm SM}$, so that it
can be made as large as the rate expected for Majorana neutrinos with only
Standard Model interactions. A non-negligible primordial abundance of
right-handed neutrinos can only worsen the situation, increasing $\Gamma_{\rm
D}^{\rm BSM}$ by 30 to 90\%. On the other hand, if a much lower total rate is
measured than what is expected for $\Gamma_{\rm D}^{\rm SM}$, it may be a sign
of new physics.

High Energy Physics - Phenomenology;Cosmology and Nongalactic Astrophysics