Following a scheme inspired by recent results of B. Feigon,
who obtained what she called a local relative trace formula for
and a local Kuznetsov
trace formula for
,
we describe the spectral side of a local relative trace formula for
relative to the
symmetric subgroup
where
is an unramified quadratic extension of local nonarchimedean fields of characteristic
. The
spectral side is given in terms of regularized normalized periods and normalized
-functions
of Harish-Chandra. Using the geometric side of the local relative trace formula obtained
in a more general setting by the authors and S. Souaifi, we deduce a local relative trace
formula for
relative to
.
We apply our result to invert some orbital integrals.
Keywords
$p$-adic reductive groups, symmetric spaces, local relative
trace formula, truncated kernel, regularized periods