  (abridged) Thanks to the recent discovery by Fermi of about fifty new
gamma-ray pulsars, it becomes possible to look for statistical properties of
their pulsed high-energy emission, especially their light-curves and
phase-resolved spectra. These pulsars emit by definition mostly gamma-ray
photons but some of them are also detected in the radio band. For those seen in
these two extreme energies, the relation between time lag of radio/gamma-ray
pulses and gamma-ray peak separation, in case both high-energy pulses are seen,
helps to put some constrain on the magnetospheric emission mechanisms and
location. This idea is analyzed in detail in this paper, assuming a polar cap
model for the radio pulses and the striped wind geometry for the pulsed
high-energy counterpart.
  Combining the time-dependent emissivity in the wind, supposed to be inverse
Compton radiation, with a simple polar cap emission model along and around the
magnetic axis, we compute the radio and gamma-ray light-curves, summarizing the
results in several phase plots. The phase lag as well as the gamma-ray peak
separation dependence on the pulsar inclination angle and on the viewing angle
are studied. Using the gamma-ray pulsar catalog compiled from the Fermi data,
we are able to predict the radio lag/peak separation relation and compare it
with available observations taken from this catalog.
