𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Bari–Markus property for Riesz projections of 1D periodic Dirac operators

✍ Scribed by P. Djakov; B. Mityagin


Publisher
John Wiley and Sons
Year
2010
Tongue
English
Weight
202 KB
Volume
283
Category
Article
ISSN
0025-584X

No coin nor oath required. For personal study only.

✦ Synopsis


Abstract

The Dirac operators

equation image

with L^2^‐potentials

equation image

considered on [0, π] with periodic, antiperiodic or Dirichlet boundary conditions (bc), have discrete spectra, and the Riesz projections

equation image

are well‐defined for |n | ≥ N if N is sufficiently large. It is proved that

equation image

where P^0^ ~n~, n ∈ ℤ, are the Riesz projections of the free operator.

Then, by the Bari–Markus criterion, the spectral Riesz decompositions

equation image

converge unconditionally in L^2^ (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)