Research output: Contribution to journal › Article › peer-review
Behavior of waveguide scattering matrices in a neighborhood of thresholds. / Plamenevskii, B. A.; Poretskii, A. S.
In: St. Petersburg Mathematical Journal, Vol. 30, No. 2, 2019, p. 285-319.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Behavior of waveguide scattering matrices in a neighborhood of thresholds
AU - Plamenevskii, B. A.
AU - Poretskii, A. S.
PY - 2019
Y1 - 2019
N2 - A waveguide occupies a d+1-dimensional domain with several cylindrical outlets to infinity. The waveguide is described by a general elliptic boundary value problem with spectral parameter μ, selfadjoint with respect to the Green formula. At infinity, the coefficients of the problem stabilize at an exponential rate to functions independent of the axial variable in the corresponding cylinder. On every interval of the continuous spectrum between neighboring "thresholds", a unitary scattering matrix S(μ) is defined; the size of S(μ) is finite for any μ, remains to be constant on any such interval, and varies from an interval to an interval. The basic result claims the existence of finite one-sided limits of the scattering matrix S(μ) at every threshold.
AB - A waveguide occupies a d+1-dimensional domain with several cylindrical outlets to infinity. The waveguide is described by a general elliptic boundary value problem with spectral parameter μ, selfadjoint with respect to the Green formula. At infinity, the coefficients of the problem stabilize at an exponential rate to functions independent of the axial variable in the corresponding cylinder. On every interval of the continuous spectrum between neighboring "thresholds", a unitary scattering matrix S(μ) is defined; the size of S(μ) is finite for any μ, remains to be constant on any such interval, and varies from an interval to an interval. The basic result claims the existence of finite one-sided limits of the scattering matrix S(μ) at every threshold.
KW - Analytic continuation
KW - Dispersion relations
KW - Elliptic problems
KW - One-sided limits at thresholds
KW - Stable basis of waves
UR - http://www.scopus.com/inward/record.url?scp=85056271067&partnerID=8YFLogxK
U2 - 10.1090/spmj/1543
DO - 10.1090/spmj/1543
M3 - Article
AN - SCOPUS:85056271067
VL - 30
SP - 285
EP - 319
JO - St. Petersburg Mathematical Journal
JF - St. Petersburg Mathematical Journal
SN - 1061-0022
IS - 2
ER -
ID: 50415309