{"id":{"repo_id":"cambridge","oai_identifier":"oai:www.repository.cam.ac.uk:1810/313149"},"canonical_url":"https://search.dev.ndltd.org/etd/cambridge/oai:www.repository.cam.ac.uk:1810/313149","repository":{"repo_id":"cambridge","name":"Cambridge University","base_url":"https://api.repository.cam.ac.uk/server/oai/request"},"display":{"title":"Separability within alternating groups and randomness","abstract":"This thesis promotes known residual properties of free groups, surface groups, right angled Coxeter groups and right angled Artin groups to the situation where the quotient is only allowed to be an alternating group. The proofs follow two related threads of ideas. The first thread leads to `alternating' analogues of extended residual finiteness in surface groups \\cite{scott1978subgroups}, right angled Artin groups and right angled Coxeter groups \\cite{haglund2008finite}. Let $W$ be a right-angled Coxeter group corresponding to a finite non-discrete graph $\\mathcal{G}$ with at least $3$ vertices. Our main theorem says that $\\mathcal{G}^c$ is connected if and only if for any infinite index convex-cocompact subgroup $H$ of $W$ and any finite subset $\\{ \\gamma_1, \\ldots , \\gamma_n \\} \\subset W \\setminus H$ there is a surjective homomorphism $f$ from $W$ to a finite alternating group such that $f (\\gamma_i) \\notin f (H)$ . A corollary is that a right-angled Artin group splits as a direct product of cyclic groups and groups with many alternating quotients in the above sense. Similarly, finitely generated subgroups of closed, orientable, hyperbolic surface groups can be separated from finitely many elements in an alternating quotient, answering positively a conjecture of Wilton \\cite{wilton2012alternating}. The second thread uses probabilistic methods to provide `alternating' analogues of subgroup conjugacy separability and subgroup into-conjugacy separability in free groups \\cite{bogopolski2010subgroup}. Suppose $H_1, \\ldots H_k$ are infinite index, finitely generated subgroups of a non-abelian free group $F$. Then there exists a surjective homomorphism $f:F \\longrightarrow A_m$ such that if $H_i$ is not conjugate into $H_j$, then $f(H_i)$ is not conjugate into $f(H_j)$.","abstract_html":"This thesis promotes known residual properties of free groups, surface groups, right angled Coxeter groups and right angled Artin groups to the situation where the quotient is only allowed to be an alternating group. The proofs follow two related threads of ideas. The first thread leads to `alternating&#x27; analogues of extended residual finiteness in surface groups \\cite{scott1978subgroups}, right angled Artin groups and right angled Coxeter groups \\cite{haglund2008finite}. Let $W$ be a right-angled Coxeter group corresponding to a finite non-discrete graph $\\mathcal{G}$ with at least $3$ vertices. Our main theorem says that <span class=\"etd-inline-math\">\\mathcal{G}<sup>c</sup></span> is connected if and only if for any infinite index convex-cocompact subgroup $H$ of $W$ and any finite subset <span class=\"etd-inline-math\">\\{ &gamma;<sub>1</sub>, \\ldots , &gamma;<sub>n</sub> \\} \\subset W \\setminus H</span> there is a surjective homomorphism $f$ from $W$ to a finite alternating group such that <span class=\"etd-inline-math\">f (&gamma;<sub>i</sub>) \\notin f (H)</span> . A corollary is that a right-angled Artin group splits as a direct product of cyclic groups and groups with many alternating quotients in the above sense. Similarly, finitely generated subgroups of closed, orientable, hyperbolic surface groups can be separated from finitely many elements in an alternating quotient, answering positively a conjecture of Wilton \\cite{wilton2012alternating}. The second thread uses probabilistic methods to provide `alternating&#x27; analogues of subgroup conjugacy separability and subgroup into-conjugacy separability in free groups \\cite{bogopolski2010subgroup}. Suppose <span class=\"etd-inline-math\">H<sub>1</sub>, \\ldots H<sub>k</sub></span> are infinite index, finitely generated subgroups of a non-abelian free group $F$. Then there exists a surjective homomorphism <span class=\"etd-inline-math\">f:F \\longrightarrow A<sub>m</sub></span> such that if <span class=\"etd-inline-math\">H<sub>i</sub></span> is not conjugate into <span class=\"etd-inline-math\">H<sub>j</sub></span>, then <span class=\"etd-inline-math\">f(H<sub>i</sub>)</span> is not conjugate into <span class=\"etd-inline-math\">f(H<sub>j</sub>)</span>.","abstract_has_math":true,"creators":["Buran, Michal"],"institution":"University of Cambridge","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Wilton, Henry"],"committee_chairs":[],"committee_members":[],"year":2020,"date_issued":"2020-07-24","date_published":"2020-07-24","updated_at":"2026-07-22T22:23:59Z","subjects":["Geometric group theory","Free groups","Residual properties","Probabilistic method"],"languages":["eng"],"rights":[],"rights_urls":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/dd397889-a4d2-4add-b3ce-45f5044db905/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"identifier_entries":[{"key":"dc:creator.authoridentifier","label":"Author Identifier","values":["0000000163699478"],"render_values":[{"text":"0000-0001-6369-9478","href":"https://orcid.org/0000-0001-6369-9478","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.17863/CAM.60253","outbound_label":"DOI","outbound_source":"dc:identifier.doi"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Wilton, Henry"]},{"key":"dc:contributor.sponsor","label":"Sponsor","values":["EPSRC International Doctoral Scholar scheme"]},{"key":"dc:creator","label":"Author","values":["Buran, Michal"]},{"key":"dc:creator.authoridentifier","label":"Author Identifier","values":["0000000163699478"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2020-07-24"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cambridge"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["https://www.repository.cam.ac.uk/handle/1810/313149"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Geometric group theory","Free groups","Residual properties","Probabilistic method"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/dd397889-a4d2-4add-b3ce-45f5044db905/download","https://www.rioxx.net/licenses/all-rights-reserved/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.17863/CAM.60253"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/9ee5efac-dcd7-46c4-800d-7c4a1a78dd29/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This thesis promotes known residual properties of free groups, surface groups, right angled Coxeter groups and right angled Artin groups to the situation where the quotient is only allowed to be an alternating group. The proofs follow two related threads of ideas. The first thread leads to `alternating' analogues of extended residual finiteness in surface groups \\cite{scott1978subgroups}, right angled Artin groups and right angled Coxeter groups \\cite{haglund2008finite}. Let $W$ be a right-angled Coxeter group corresponding to a finite non-discrete graph $\\mathcal{G}$ with at least $3$ vertices. Our main theorem says that $\\mathcal{G}^c$ is connected if and only if for any infinite index convex-cocompact subgroup $H$ of $W$ and any finite subset $\\{ \\gamma_1, \\ldots , \\gamma_n \\} \\subset W \\setminus H$ there is a surjective homomorphism $f$ from $W$ to a finite alternating group such that $f (\\gamma_i) \\notin f (H)$ . A corollary is that a right-angled Artin group splits as a direct product of cyclic groups and groups with many alternating quotients in the above sense. Similarly, finitely generated subgroups of closed, orientable, hyperbolic surface groups can be separated from finitely many elements in an alternating quotient, answering positively a conjecture of Wilton \\cite{wilton2012alternating}. The second thread uses probabilistic methods to provide `alternating' analogues of subgroup conjugacy separability and subgroup into-conjugacy separability in free groups \\cite{bogopolski2010subgroup}. Suppose $H_1, \\ldots H_k$ are infinite index, finitely generated subgroups of a non-abelian free group $F$. Then there exists a surjective homomorphism $f:F \\longrightarrow A_m$ such that if $H_i$ is not conjugate into $H_j$, then $f(H_i)$ is not conjugate into $f(H_j)$."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["4138db6d6ccbd87589565fe44d108525","353adac0d1ebdfd65ab16480263c3c87"]},{"key":"dc:title","label":"Title","values":["Separability within alternating groups and randomness"]}]}],"canonical_facts":{"dc:contributor.advisor":["Wilton, Henry"],"dc:contributor.sponsor":["EPSRC International Doctoral Scholar scheme"],"dc:creator":["Buran, Michal"],"dc:creator.authoridentifier":["0000000163699478"],"dc:date.issued":["2020-07-24"],"dc:description.abstract":["This thesis promotes known residual properties of free groups, surface groups, right angled Coxeter groups and right angled Artin groups to the situation where the quotient is only allowed to be an alternating group. The proofs follow two related threads of ideas. The first thread leads to `alternating' analogues of extended residual finiteness in surface groups \\cite{scott1978subgroups}, right angled Artin groups and right angled Coxeter groups \\cite{haglund2008finite}. Let $W$ be a right-angled Coxeter group corresponding to a finite non-discrete graph $\\mathcal{G}$ with at least $3$ vertices. Our main theorem says that $\\mathcal{G}^c$ is connected if and only if for any infinite index convex-cocompact subgroup $H$ of $W$ and any finite subset $\\{ \\gamma_1, \\ldots , \\gamma_n \\} \\subset W \\setminus H$ there is a surjective homomorphism $f$ from $W$ to a finite alternating group such that $f (\\gamma_i) \\notin f (H)$ . A corollary is that a right-angled Artin group splits as a direct product of cyclic groups and groups with many alternating quotients in the above sense. Similarly, finitely generated subgroups of closed, orientable, hyperbolic surface groups can be separated from finitely many elements in an alternating quotient, answering positively a conjecture of Wilton \\cite{wilton2012alternating}. The second thread uses probabilistic methods to provide `alternating' analogues of subgroup conjugacy separability and subgroup into-conjugacy separability in free groups \\cite{bogopolski2010subgroup}. Suppose $H_1, \\ldots H_k$ are infinite index, finitely generated subgroups of a non-abelian free group $F$. Then there exists a surjective homomorphism $f:F \\longrightarrow A_m$ such that if $H_i$ is not conjugate into $H_j$, then $f(H_i)$ is not conjugate into $f(H_j)$."],"dc:format.checksum.md5":["4138db6d6ccbd87589565fe44d108525","353adac0d1ebdfd65ab16480263c3c87"],"dc:identifier.doi":["10.17863/CAM.60253"],"dc:identifier.uri":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/9ee5efac-dcd7-46c4-800d-7c4a1a78dd29/download"],"dc:language":["eng"],"dc:publisher.institution":["University of Cambridge"],"dc:relation.isreferencedby.uri":["https://www.repository.cam.ac.uk/handle/1810/313149"],"dc:rights":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/dd397889-a4d2-4add-b3ce-45f5044db905/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"dc:subject":["Geometric group theory","Free groups","Residual properties","Probabilistic method"],"dc:title":["Separability within alternating groups and randomness"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-22T22:23:59Z"}