The paper studies homogenization problem for a bounded in
L2(Rd)
convolution type operator
A\eps,
\eps >0, of the form
({\mathbb A}_\eps u) (\x) = \eps^{-d-2} \int_{\R^d} a((\x-\y)/\eps)
\mu(\x/\eps, \y/\eps) \left( u(\x) - u(\y) \right)\,d\y.
It is assumed that
a(\x) is a non-negative function from
L1(Rd), and
μ(\x,\y) is a
periodic in
\x and
\y function such that $0< \mu_- \leqslant \mu(\x,\y)
\leqslant \mu_+< \infty
.Nosymmetryassumptionona(\cdot)
and\mu(\cdot)$
is imposed, so the operator
A\eps need not be self-adjoint. Under
the assumption that the moments
Mk=∫Rd∣\x∣ka(\x)d\x,
k=1,2,3, are finite we obtain, for small
\eps>0, sharp in order
approximation of the resolvent
(A\eps+I)−1 in the operator
norm in
L2(Rd), the discrepancy being of order
O(\eps). The
approximation is given by an operator of the form $({\mathbb A}^0 + \eps^{-1}
\langle \boldsymbol{\alpha},\nabla \rangle + I)^{-1}$ multiplied on the right
by a periodic function
q0(\x/\eps); here ${\mathbb A}^0 = -
\operatorname{div}g^0 \nabla$ is the effective operator, and
α is a constant vector.