  Thermoelectric phenomena resulting from an interplay between particle flows
induced by electric fields and temperature inhomogeneities are extremely
insightful as a tool providing substantial knowledge about the microscopic
structure of a given system. Tuning, e.g., parameters of a nanoscopic system
coupled via tunneling mechanisms to two contacts one may achieve various
situations where the electric current induced by an external bias voltage
competes with the electric current excited by the temperature difference of the
two contacts. Even more exciting physics emerges when the system's electronic
degrees freedom split to form Majorana fermions which make the thermoelectric
dynamics universal. Here we propose revealing this unique universal signatures
of Majorana fermions in strongly nonequilibrium quantum dots via noise of the
thermoelectric transport beyond linear response. It is demonstrated that
whereas mean thermoelectric quantities are only universal at large bias
voltages, the noise of the electric current excited by an external bias voltage
and the temperature difference of the contacts is universal at any bias
voltage. We provide truly universal, i.e. independent of the system's
parameters, thermoelectric ratios between nonlinear response coefficients of
the noise and mean current at large bias voltages where experiments may easily
be performed to uniquely detect these truly universal Majorana thermoelectric
signatures.
