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/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

In 1980, Yang and Yau [ 20 ] proved the celebrated upper bound for the first eigenvalue on an orientable surface of genus   $\gamma $  . Later Li and Yau [ 14 ] gave a simple proof of this bound by introducing the concept of conformal volume of a Riemannian manifold. In the same paper, they proposed an approach for obtaining a similar estimate for non-orientable surfaces. In the present paper, we formalize their argument and improve the bounds stated in [ 14 ].

Upper Bounds for the First Eigenvalue of the Laplacian on Non-Orientable Surfaces