  Gluon-initiated double Higgs production is the most important channel to
extract the Higgs self-coupling at hadron colliders. However, new physics could
enter into this channel in several distinctive ways including, but not limited
to, the Higgs self-coupling, a modified top Yukawa coupling, and an anomalous
Higgs-top quartic coupling. In this work we initiate a study on the interplay
of these effects in the kinematic distributions of the Higgs bosons. More
specifically, we divide the transverse momentum and the total invariant mass
spectra into two bins and use the differential rates in each bin to constrain
the magnitude of the aforementioned effects. Significantly improved results
could be obtained over those using total cross section alone. However, some
degeneracy remains, especially in the determination of the Higgs trilinear
coupling. Therefore, an accurate measurement of the Higgs self-coupling in this
channel would require precise knowledge of the magnitudes of other new physics
effects. We base our analysis on a future 100 TeV proton-proton collider.
