English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

An algebraic Riccati equation for linear operators is studied, which arisesin systems theory. For the case that all involved operators are unbounded, theexistence of infinitely many selfadjoint solutions is shown. To this end,invariant graph subspaces of the associated Hamiltonian operator matrix areconstructed by means of a Riesz basis with parentheses of generalisedeigenvectors and two indefinite inner products. Under additional assumptions,the existence and a representation of all bounded solutions is obtained. Thetheory is applied to Riccati equations of differential operators.

Hamiltonians with Riesz Bases of Generalised Eigenvectors and Riccati Equations