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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We consider the propagation of acoustic, electromagnetic and elastic waves ina one-dimensional periodic two-component material. Accurate asymptotic formulasare provided for the group velocity as a function of the material parameterswhen the concentration of scatterers is small or the characteristic impedancesof the two media differ substantially. In the latter case, it is shown that theminimum group velocity occurs when the volume fractions of the components ofthe material are equal. In both asymptotic cases we show that the leading termsof the group velocity do not depend on frequency. Thus slowdown isfrequency-independent and is not related to the resonance phenomena.

Slowdown of group velocity in periodic waveguides