  We prove a Kn"orrer periodicity type equivalence between derived
factorization categories of gauged LG models, which is an analogy of a theorem
proved by Shipman and Isik independently. As an application, we obtain a gauged
LG version of Orlov's theorem describing a relationship between categories of
graded matrix factorizations and derived categories of hypersurfaces in
projective spaces, by combining the above Kn"orrer periodicity type equivalence
and the theory of variations of GIT quotients due to Ballard, Favero and
Katzarkov.
