  The periods of magnetic activity cycles in the Sun and solar-type stars do
not exhibit a simple or even single trend with respect to rotation rate or
luminosity. Dynamo models can be used to interpret this diversity, and can
ultimately help us understand why some solar-like stars do not exhibit a
magnetic cycle, whereas some do, and for the latter what physical mechanisms
set their magnetic cycle period. Three-dimensional non-linear
magnetohydrodynamical simulations present the advantage of having only a small
number of tunable parameters, and produce in a dynamically self-consistent
manner the flows and the dynamo magnetic fields pervading stellar interiors. We
conducted a series of such simulations within the EULAG-MHD framework, varying
the rotation rate and luminosity of the modeled solar-like convective
envelopes. We find decadal magnetic cycles when the Rossby number near the base
of the convection zone is moderate (typically between 0.25 and 1). Secondary,
shorter cycles located at the top of the convective envelope close to the
equator are also observed in our numerical experiments, when the local Rossby
number is lower than 1. The deep-seated dynamo sustained in these numerical
experiments is fundamentally non-linear, in that it is the feedback of the
large-scale magnetic field on the large-scale differential rotation that sets
the magnetic cycle period. The cycle period is found to decrease with the
Rossby number, which offers an alternative theoretical explanation to the
variety of activity cycles observed in solar-like stars.
