Hosted on Zoom by the University of Birmingham<\/a> Zoom Link: <\/b>The meeting will be held online via Zoom. You can click here<\/a> to join.<\/p>\n Schedule (all GMT times):<\/b><\/p>\n All talks are 30 minutes followed by 15 minutes of questions and discussion.<\/p>\n Titles and Abstracts:<\/b><\/p>\n Speaker: Eric Finster<\/strong> Speaker: Matteo Spadetto<\/strong> Taking advantage of Hofstra's recent work relating the generalised version of de Paiva's construction to the notions of existential and universal completion of a given fibration, we characterise the instances of the dialectica completion, showing that these are precisely the G\u00f6del fibrations. Secondly we mention some principles and rules that are involved in the Dialectica interpretation and that these fibrations satisfy. Finally, we describe the categorical (logical) structures that behave well with respect to this construction, comparing the proof irrelevant setting to the proof relevant one. The talk is based on joint work with Davide Trotta (University of Pisa) and Valeria de Paiva (Topos Institute). Speaker: Tom\u00e1\u0161 Jakl<\/strong> I will give an overivew of the emerging theory of game comonads and an ongoing work with Dan Marsden and Nihil Shah where we prove various Feferman\u2013Vaught-Mostowski-type theorems, which are behind Courcelle's celebrated theorem. Speaker: Zeinab Galal<\/strong> <\/p>\n","protected":false},"excerpt":{"rendered":"January 10, 2022 Hosted on Zoom by the University of Birmingham Supported by the London Mathematical Society Zoom Link: The meeting will be held online via Zoom. You can click here to join. Schedule (all GMT times): 10:30-10:35 Welcome 10:35-11:20 Eric Finster (University of Birmingham) 11:20-12:05 Matteo Spadetto (University of Leeds) 12:05-13:30 Lunch break 13:30-14:15...","protected":false},"author":134,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-168","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/conferences.leeds.ac.uk\/yamcats\/wp-json\/wp\/v2\/pages\/168","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/conferences.leeds.ac.uk\/yamcats\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/conferences.leeds.ac.uk\/yamcats\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/conferences.leeds.ac.uk\/yamcats\/wp-json\/wp\/v2\/users\/134"}],"replies":[{"embeddable":true,"href":"https:\/\/conferences.leeds.ac.uk\/yamcats\/wp-json\/wp\/v2\/comments?post=168"}],"version-history":[{"count":0,"href":"https:\/\/conferences.leeds.ac.uk\/yamcats\/wp-json\/wp\/v2\/pages\/168\/revisions"}],"wp:attachment":[{"href":"https:\/\/conferences.leeds.ac.uk\/yamcats\/wp-json\/wp\/v2\/media?parent=168"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nSupported by the London Mathematical Society<\/a><\/p>\n\n
\nTitle: Infinitely Connected Objects<\/strong>
\nAbstract: <\/b>One interesting aspect of \u221e-topos theory which separates it from classical homotopy theory is the existence of objects which have trivial homotopy groups in every dimension, but which nonetheless are not contractible. We say such objects are \u221e-connected<\/i>. In this short talk, I will give a quick introduction to this notion and describe the main sources of examples.
\nSlides<\/b>: here<\/a><\/p>\n
\nTitle: Dialectica completion & dialectica logical principles<\/strong>
\nAbstract: <\/b>The notion of dialectica construction associated to a finitely complete category, an attempt of providing a categorical version of G\u00f6del's Dialectica interpretation, was introduced by de Paiva in her PhD thesis and then generalised by Hyland and Biering to an arbitrary fibration. In this talk we introduce the notion of G\u00f6del fibration, which categorically embodies both the logical principles of traditional Skolemization and the existence of a prenex normal form presentation for every formula. A G\u00f6del fibration is defined by a list of categorical properties, essentially saying that it has \"enough\" existential quantifier free and universal quantifier free predicates.<\/p>\n
\nSlides:\u00a0<\/b>here<\/a><\/p>\n
\nTitle: Game comonads and Courcelle's theorem<\/strong>
\nAbstract:\u00a0 <\/b>In the recent years comonads encoding positions in model comparison games have been successfully applied to study a range of imporatnt notions in finite model theory and combinatorics.<\/p>\n
\nSlides: <\/b>here<\/a><\/p>\n
\nTitle: Finiteness species of structures<\/strong>
\nAbstract: <\/b>Finiteness spaces were introduced by Ehrhard as a refinement of the relational model of linear logic. A finiteness space is a set equipped with a class of finitary subsets which can be thought of being subsets that behave like finite sets. A morphism between finiteness spaces is a relation that preserves the finitary structure. This model allows for a finer analysis of the computational aspects of the relational model and it provided a semantical motivation for differential linear logic and the syntactic notion of Taylor expansion. In this talk, I will present a bicategorical generalization of this construction where the relational model is replaced with the model of generalized species of structures introduced by Fiore, Gambino, Hyland and Winskel and the finiteness property now relies on finite presentability.
\nSlides: <\/b>here<\/a><\/p>\n