BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Jason Parker (Brandon) DTSTART;VALUE=DATE-TIME:20210430T150000Z DTEND;VALUE=DATE-TIME:20210430T170000Z DTSTAMP;VALUE=DATE-TIME:20240328T181829Z UID:LogicSupergroup/1 DESCRIPTION:Title: Isotropy Groups of Quasi-Equational Theories\nby Jason Parker (Brandon) as part of Logic Supergroup\n\n\nAbstract\nIn [2]\, my PhD super visors (Pieter Hofstra and Philip Scott) and I studied the new topos-theor etic phenomenon of isotropy (as introduced in [1]) in the context of singl e-sorted algebraic theories\, and we gave a logical/syntactic characteriza tion of the\nisotropy group of any such theory\, thereby showing that it e ncodes a notion of inner automorphism or conjugation for the theory. In th e present talk\, I will summarize the results of my recent PhD thesis\, in which I build on this earlier work by studying the isotropy groups of (mu lti-sorted) quasi-equational theories (also known as essentially algebraic \, cartesian\, or finite limit theories). In particular\, I will show how to give a logical/syntactic characterization of the isotropy group of any such theory\, and that it encodes a notion of inner automorphism or conjug ation for the theory. I will also describe how I have used this characteri zation to exactly characterize the ‘inner automorphisms’ for several d ifferent examples of quasi-equational theories\, most notably the theory o f strict monoidal categories and the theory of presheaves valued in a cate gory of models. In particular\, the latter example provides a characteriza tion of the (covariant) isotropy group of a category of set-valued preshea ves\, which had been an open question in the theory of categorical isotrop y. \n\n[1] J. Funk\, P. Hofstra\, B. Steinberg. Isotropy and crossed topos es. Theory and Applications of Categories 26\, 660-709\, 2012.\n\n[2] P. H ofstra\, J. Parker\, P.J. Scott. Isotropy of algebraic theories. Electroni c Notes in Theoretical Computer Science 341\, 201-217\, 2018.\n\nhttps://s ites.google.com/view/logicsupergroup/\n LOCATION:https://researchseminars.org/talk/LogicSupergroup/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Romina Padro (CUNY) DTSTART;VALUE=DATE-TIME:20210507T150000Z DTEND;VALUE=DATE-TIME:20210507T170000Z DTSTAMP;VALUE=DATE-TIME:20240328T181829Z UID:LogicSupergroup/2 DESCRIPTION:by Romina Padro (CUNY) as part of Logic Supergroup\n\nAbstract : TBA\n LOCATION:https://researchseminars.org/talk/LogicSupergroup/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Francesca Boccuni & Luca Zanetti (Vita-Salute San Raffaele & IUSS Pavia) DTSTART;VALUE=DATE-TIME:20210514T150000Z DTEND;VALUE=DATE-TIME:20210514T170000Z DTSTAMP;VALUE=DATE-TIME:20240328T181829Z UID:LogicSupergroup/3 DESCRIPTION:Title: How to Hamlet a Caesar\nby Francesca Boccuni & Luca Zanetti (V ita-Salute San Raffaele & IUSS Pavia) as part of Logic Supergroup\n\n\nAbs tract\nNeologicism aims at providing a foundation for arithmetic on the ba sis of so-called Hume's Principle (HP)\, which states that the number of t he Fs is identical with the number of the Gs iff there is one-to-one corre spondence between the concepts F and G. Philosophically\, Neologicism amou nts to three main claims: (1) HP is analytic\; (2) HP is \;a priori \; (3) HP captures the nature of cardinal numbers. Nevertheless\, Neol ogicism is faced with the so-called \;Caesar problem: though HP provides an implicit definition of the concept \;Cardinal Number i>\, which arguably might be known a priori\, HP does not determine the tr uth-value of mixed identity statements such as "Caesar=4". Neologicists ta ckle the Caesar problem by claiming that the applicability conditions of t he concept \;Cardinal Number \;can be obtained from the ide ntity conditions determined by HP\, so that the truth of mixed identity st atements as "Caesar=4" can be determined in the negative. In this talk\, w e will argue that the Neologicist solution to the Caesar problem gives ris e to what we call the \;Caesar Problem problem: if the Caesar p roblem is indeed solved as Neologicists claim\, then (1)-(3) cannot be joi ntly argued for. \;We will consider some ways in which Neologicists ca n try to solve the Caesar Problem problem\, and we will argue that none of these solutions are favourable to them. Finally\, we will investigate the consequences of the Caesar Problem problem for Neologicism. \;
\n\ nhttps://sites.google.com/view/logicsupergroup/\n LOCATION:https://researchseminars.org/talk/LogicSupergroup/3/ END:VEVENT BEGIN:VEVENT SUMMARY:John Baldwin (UIC) DTSTART;VALUE=DATE-TIME:20210521T150000Z DTEND;VALUE=DATE-TIME:20210521T170000Z DTSTAMP;VALUE=DATE-TIME:20240328T181829Z UID:LogicSupergroup/4 DESCRIPTION:by John Baldwin (UIC) as part of Logic Supergroup\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/LogicSupergroup/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Bruno Da Re (Conicet/UBA) DTSTART;VALUE=DATE-TIME:20210528T150000Z DTEND;VALUE=DATE-TIME:20210528T170000Z DTSTAMP;VALUE=DATE-TIME:20240328T181829Z UID:LogicSupergroup/5 DESCRIPTION:by Bruno Da Re (Conicet/UBA) as part of Logic Supergroup\n\nAb stract: TBA\n LOCATION:https://researchseminars.org/talk/LogicSupergroup/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Cristóbal Rojas (Andrés Bello) DTSTART;VALUE=DATE-TIME:20210611T150000Z DTEND;VALUE=DATE-TIME:20210611T170000Z DTSTAMP;VALUE=DATE-TIME:20240328T181829Z UID:LogicSupergroup/6 DESCRIPTION:by Cristóbal Rojas (Andrés Bello) as part of Logic Supergrou p\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/LogicSupergroup/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Verónica Becher (Universidad de Buenos Aires) DTSTART;VALUE=DATE-TIME:20210618T010000Z DTEND;VALUE=DATE-TIME:20210618T030000Z DTSTAMP;VALUE=DATE-TIME:20240328T181829Z UID:LogicSupergroup/7 DESCRIPTION:Title: Random!\nby Verónica Becher (Universidad de Buenos Aires) as part of Logic Supergroup\n\n\nAbstract\nEveryone has an intuitive idea abo ut what randomness is\, often associated with "gambling" or "luck". Is the re a mathematical definition of randomness? Are there degrees of randomnes s? Can we give examples of randomness? Can a computer produce a sequence t hat is truly random? What is the relation between randomness\, logic\, lan guage and information? I will talk about these questions and their answers .\n LOCATION:https://researchseminars.org/talk/LogicSupergroup/7/ END:VEVENT END:VCALENDAR