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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In this article, we present a simple criterion for checking whether aone-parameter matrix group of dilations admits a continuous wavelet. Thiscriterion involves only checking that the eigenvalues of the symmetric part ofthe matrix have the same sign. In $R^2$ this criterion gives a completecharacterization of such matrix groups.

An Elementary Eigenvalue Criterion for One-Parameter Dilation Groups to Admit a Continuous Wavelet