文摘
We consider a quantitative form of the quasi-isometry problem. We discuss several arguments which lead us to a number of results and bounds of quasi-isometric distortion: comparison of volumes, connectivity, etc. Then we study the transport of Poincaré constants by quasi-isometries and we give sharp lower and upper bounds for the homotopy distortion growth for a certain class of hyperbolic metric spaces, a quotient of a Heintze group id="mmlsi1" class="mathmlsrc">ixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022123615003699&_mathId=si1.gif&_user=111111111&_pii=S0022123615003699&_rdoc=1&_issn=00221236&md5=e1871332a5524dfddff425dd91f257ca" title="Click to view the MathML source">R鈰塕niner hidden"> by id="mmlsi2" class="mathmlsrc">ixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022123615003699&_mathId=si2.gif&_user=111111111&_pii=S0022123615003699&_rdoc=1&_issn=00221236&md5=4d067fc699857295a84b05e41bbed668" title="Click to view the MathML source">Zniner hidden">. We also prove the linear distortion growth between hyperbolic space id="mmlsi3" class="mathmlsrc">ixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022123615003699&_mathId=si3.gif&_user=111111111&_pii=S0022123615003699&_rdoc=1&_issn=00221236&md5=4318951dfc903b88c1c20b240932d983" title="Click to view the MathML source">Hn,n≥3iner hidden"> and a tree.