Improving dimension estimates for Furstenberg-type sets

In this paper we study the problem of estimating the generalized Hausdorff dimension of Furstenberg sets in the plane. For α∈(0,1], a set F in the plane is said to be an α-Furstenberg set if for each direction e there is a line segment ℓe in the direction of e for which dimH(ℓe∩F)⩾α. It is well know...

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Detalles Bibliográficos
Autores: Molter, Úrsula María, Rela, Ezequiel
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2010
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/47720
Acceso en línea:http://hdl.handle.net/11441/47720
https://doi.org/10.1016/j.aim.2009.08.019
Access Level:acceso abierto
Palabra clave:Furstenberg sets
Hausdorff dimension
Dimension function
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spelling Improving dimension estimates for Furstenberg-type setsMolter, Úrsula MaríaRela, EzequielFurstenberg setsHausdorff dimensionDimension functionIn this paper we study the problem of estimating the generalized Hausdorff dimension of Furstenberg sets in the plane. For α∈(0,1], a set F in the plane is said to be an α-Furstenberg set if for each direction e there is a line segment ℓe in the direction of e for which dimH(ℓe∩F)⩾α. It is well known that , and it is also known that these sets can have zero measure at their critical dimension. By looking at general Hausdorff measures Hh defined for doubling functions, that need not be power laws, we obtain finer estimates for the size of the more general h-Furstenberg sets. Further, this approach allow us to sharpen the known bounds on the dimension of classical Furstenberg sets. The main difficulty we had to overcome, was that if Hh(F)=0, there always exists g≺h such that Hg(F)=0 (here ≺ refers to the natural ordering on general Hausdorff dimension functions). Hence, in order to estimate the measure of general Furstenberg sets, we have to consider dimension functions that are a true step down from the critical one. We provide rather precise estimates on the size of this step and by doing so, we can include a family of zero dimensional Furstenberg sets associated to dimension functions that grow faster than any power function at zero. With some additional growth conditions on these zero dimensional functions, we extend the known inequalities to include the endpoint α=0.Agencia Nacional de Promoción Científica y Tecnológica (Argentina)Universidad de Buenos AiresElsevierAnálisis MatemáticoAgencia Nacional de Promoción Científica y Tecnológica. ArgentinaUniversidad de Buenos Aires2010info:eu-repo/semantics/articleinfo:eu-repo/semantics/submittedVersionapplication/pdfapplication/pdfhttp://hdl.handle.net/11441/47720https://doi.org/10.1016/j.aim.2009.08.019reponame:idUS. Depósito de Investigación de la Universidad de Sevillainstname:Universidad de Sevilla (US)InglésAdvances in Mathematics, 223 (2), 672-688.PICT2006-00177UBACyT X149http://ac.els-cdn.com/S0001870809002667/1-s2.0-S0001870809002667-main.pdf?_tid=4445e7d4-95c3-11e6-aa03-00000aab0f26&acdnat=1476857837_1cb593375dcb252175720f3c881b1704info:eu-repo/semantics/openAccessoai:idus.us.es:11441/477202026-06-17T12:51:07Z
dc.title.none.fl_str_mv Improving dimension estimates for Furstenberg-type sets
title Improving dimension estimates for Furstenberg-type sets
spellingShingle Improving dimension estimates for Furstenberg-type sets
Molter, Úrsula María
Furstenberg sets
Hausdorff dimension
Dimension function
title_short Improving dimension estimates for Furstenberg-type sets
title_full Improving dimension estimates for Furstenberg-type sets
title_fullStr Improving dimension estimates for Furstenberg-type sets
title_full_unstemmed Improving dimension estimates for Furstenberg-type sets
title_sort Improving dimension estimates for Furstenberg-type sets
dc.creator.none.fl_str_mv Molter, Úrsula María
Rela, Ezequiel
author Molter, Úrsula María
author_facet Molter, Úrsula María
Rela, Ezequiel
author_role author
author2 Rela, Ezequiel
author2_role author
dc.contributor.none.fl_str_mv Análisis Matemático
Agencia Nacional de Promoción Científica y Tecnológica. Argentina
Universidad de Buenos Aires
dc.subject.none.fl_str_mv Furstenberg sets
Hausdorff dimension
Dimension function
topic Furstenberg sets
Hausdorff dimension
Dimension function
description In this paper we study the problem of estimating the generalized Hausdorff dimension of Furstenberg sets in the plane. For α∈(0,1], a set F in the plane is said to be an α-Furstenberg set if for each direction e there is a line segment ℓe in the direction of e for which dimH(ℓe∩F)⩾α. It is well known that , and it is also known that these sets can have zero measure at their critical dimension. By looking at general Hausdorff measures Hh defined for doubling functions, that need not be power laws, we obtain finer estimates for the size of the more general h-Furstenberg sets. Further, this approach allow us to sharpen the known bounds on the dimension of classical Furstenberg sets. The main difficulty we had to overcome, was that if Hh(F)=0, there always exists g≺h such that Hg(F)=0 (here ≺ refers to the natural ordering on general Hausdorff dimension functions). Hence, in order to estimate the measure of general Furstenberg sets, we have to consider dimension functions that are a true step down from the critical one. We provide rather precise estimates on the size of this step and by doing so, we can include a family of zero dimensional Furstenberg sets associated to dimension functions that grow faster than any power function at zero. With some additional growth conditions on these zero dimensional functions, we extend the known inequalities to include the endpoint α=0.
publishDate 2010
dc.date.none.fl_str_mv 2010
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/submittedVersion
format article
status_str submittedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11441/47720
https://doi.org/10.1016/j.aim.2009.08.019
url http://hdl.handle.net/11441/47720
https://doi.org/10.1016/j.aim.2009.08.019
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Advances in Mathematics, 223 (2), 672-688.
PICT2006-00177
UBACyT X149
http://ac.els-cdn.com/S0001870809002667/1-s2.0-S0001870809002667-main.pdf?_tid=4445e7d4-95c3-11e6-aa03-00000aab0f26&acdnat=1476857837_1cb593375dcb252175720f3c881b1704
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:idUS. Depósito de Investigación de la Universidad de Sevilla
instname:Universidad de Sevilla (US)
instname_str Universidad de Sevilla (US)
reponame_str idUS. Depósito de Investigación de la Universidad de Sevilla
collection idUS. Depósito de Investigación de la Universidad de Sevilla
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