  We calculate the spin-averaged generalized parton distributions (GPDs) of sea
quarks in the proton at zero skewness from nonlocal covariant chiral effective
theory, including one-loop contributions from intermediate states with
pseudoscalar mesons and octet and decuplet baryons. A relativistic regulator is
generated from the nonlocal Lagrangian where a gauge link is introduced to
guarantee local gauge invariance, with additional diagrams from the expansion
of the gauge link ensuring conservation of electric charge and strangeness.
Flavor asymmetries for sea quarks at zero and finite momentum transfer, as well
as strange form factors, are obtained from the calculated GPDs, and results
compared with phenomenological extractions and lattice QCD.
