TY - JOUR ID - Iakovlev2013 LB - Iakovlev2013 AU - Iakovlev, Serguei I. AU - Iakovleva, Valentina TI - Eigenvalue-eigenfunction problem for Steklov's smoothing operator and differential-difference equations of mixed type ST - Eigenvalue-eigenfunction problem for Steklov's smoothing operator and differential-difference equations of mixed type JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2013 VL - 33 IS - 1 SP - 81 EP - 98 DO - http://dx.doi.org/10.7494/OpMath.2013.33.1.81 UR - http://dx.doi.org/10.7494/OpMath.2013.33.1.81 AB - It is shown that any \(\mu \in \mathbb{C}\) is an infinite multiplicity eigenvalue of the Steklov smoothing operator \(S_h\) acting on the space \(L^1_{loc}(\mathbb{R})\). For \(\mu \neq 0\) the eigenvalue-eigenfunction problem leads to studying a differential-difference equation of mixed type. An existence and uniqueness theorem is proved for this equation. Further a transformation group is defined on a countably normed space of initial functions and the spectrum of the generator of this group is studied. Some possible generalizations are pointed out. KW - Steklov's smoothing operator KW - spectrum KW - eigenvalues KW - eigenfunctions KW - mixed-type differential-difference equations KW - initial function KW - method of steps KW - countably normed space KW - transformation group KW - generator SN - 1232-9274 ER -