Substitutions with Vanishing Rotationally Invariant First Cohomology

The cohomology groups of tiling spaces with three-fold and nine-fold symmetries are obtained. The substitution tilings are characterized by the fact that they have vanishing first cohomology group in the space of tilings modulo a rotation. The rank of the rational first cohomology, in the tiling spa...

Full description

Saved in:
Bibliographic Details
Main Author: Juan García Escudero
Format: Article
Language:English
Published: Wiley 2012-01-01
Series:Discrete Dynamics in Nature and Society
Online Access:http://dx.doi.org/10.1155/2012/818549
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832554881421934592
author Juan García Escudero
author_facet Juan García Escudero
author_sort Juan García Escudero
collection DOAJ
description The cohomology groups of tiling spaces with three-fold and nine-fold symmetries are obtained. The substitution tilings are characterized by the fact that they have vanishing first cohomology group in the space of tilings modulo a rotation. The rank of the rational first cohomology, in the tiling space formed by the closure of a translational orbit, equals the Euler totient function evaluated at 𝑁 if the underlying rotation group is 𝐙𝑁. When the symmetries are of crystallographic type, the cohomologies are infinitely generated.
format Article
id doaj-art-a98a5ac3d5f94452a4651624dcf41d12
institution Kabale University
issn 1026-0226
1607-887X
language English
publishDate 2012-01-01
publisher Wiley
record_format Article
series Discrete Dynamics in Nature and Society
spelling doaj-art-a98a5ac3d5f94452a4651624dcf41d122025-02-03T05:50:16ZengWileyDiscrete Dynamics in Nature and Society1026-02261607-887X2012-01-01201210.1155/2012/818549818549Substitutions with Vanishing Rotationally Invariant First CohomologyJuan García Escudero0Facultad de Ciencias Matemáticas y Físicas, Universidad de Oviedo, 33007 Oviedo, SpainThe cohomology groups of tiling spaces with three-fold and nine-fold symmetries are obtained. The substitution tilings are characterized by the fact that they have vanishing first cohomology group in the space of tilings modulo a rotation. The rank of the rational first cohomology, in the tiling space formed by the closure of a translational orbit, equals the Euler totient function evaluated at 𝑁 if the underlying rotation group is 𝐙𝑁. When the symmetries are of crystallographic type, the cohomologies are infinitely generated.http://dx.doi.org/10.1155/2012/818549
spellingShingle Juan García Escudero
Substitutions with Vanishing Rotationally Invariant First Cohomology
Discrete Dynamics in Nature and Society
title Substitutions with Vanishing Rotationally Invariant First Cohomology
title_full Substitutions with Vanishing Rotationally Invariant First Cohomology
title_fullStr Substitutions with Vanishing Rotationally Invariant First Cohomology
title_full_unstemmed Substitutions with Vanishing Rotationally Invariant First Cohomology
title_short Substitutions with Vanishing Rotationally Invariant First Cohomology
title_sort substitutions with vanishing rotationally invariant first cohomology
url http://dx.doi.org/10.1155/2012/818549
work_keys_str_mv AT juangarciaescudero substitutionswithvanishingrotationallyinvariantfirstcohomology