Sat, 05 Jan 2019
16:15

TBA

Rahul Santhanam
(Oxford)
Thu, 24 Jan 2019
11:00
L6

Kim-independence in NSOP1 theories

Itay Kaplan
(Hebrew University)
Abstract

NSOP1 is a class of first order theories containing simple theories, which contains many natural examples that somehow slip-out of the simple context.

As in simple theories, NSOP1 theories admit a natural notion of independence dubbed Kim-independence, which generalizes non-forking in simple theories and satisfies many of its properties.

In this talk I will explain all these notions, and in particular talk about recent progress (joint with Nick Ramsey) in the study of Kim-independence, showing transitivity and several consequences.

 

Thu, 31 Jan 2019
17:00
L5

Z + PROVI

A.R.D. Mathias
(Université de la Réunion)
Abstract

Here Z is Zermelo’s set theory of 1908, as later formulated: full separation, but no replacement or collection among its axioms. PROVI was presented in lectures in Cambridge in 2010 and later published with improvements by Nathan Bowler, and is, I claim, the weakest subsystem of ZF to support a recognisable theory of set forcing: PROV is PROVI shorn of its axiom of infinity. The provident sets are the transitive non-empty models of PROV. The talk will begin with a presentation of PROV, and then discuss more recent applications and problems: in particular an answer in the system Z + PROV to a question posed by Eugene Wesley in 1972 will be sketched, and two proofs (fallacious, I hope) of 0 = 1 will be given, one using my slim models of Z and the other applying the Spector–Gandy theorem to certain models of PROVI. These “proofs”, when re-interpreted, supply some arguments of Reverse Mathematics.

Thu, 07 Feb 2019
17:00
L5

Intermediate models of ZF

Asaf Karagila
(Norwich)
Abstract

Starting with a countable transitive model of V=L, we show that by 
adding a single Cohen real, c, most intermediate models do no satisfy choice. In 
fact, most intermediate models to L[c] are not even definable.

The key part of the proof is the Bristol model, which is intermediate to L[c], 
but is not constructible from a set. We will give a broad explanation of the 
construction of the Bristol model within the constraints of time.

Thu, 14 Feb 2019
17:00
L5

A Dichotomy for Some Elementarily Generated Modal Logics

Stanislav Kikot
(Oxford)
Abstract

 The talk is about the normal modal logics of elementary classes defined by first-order formulas of the form
 'for all x_0 there exist x_1, ..., x_n phi(x_0, x_1, ... x_n)' with phi being a conjunction of binary atoms.
 I'll show that many properties of these logics, such as finite axiomatisability,
 elementarity,  axiomatisability by a set of canonical formulas or by a single generalised Sahlqvist formula,
 together with modal definability of the initial formula, either simultaneously hold or simultaneously do not hold.
 

Mon, 11 Mar 2019

17:00 - 18:00
L1

Marc Lackenby - Knotty Problems

Marc Lackenby
(University of Oxford)
Further Information

Knots are a familiar part of everyday life, for example tying your tie or doing up your shoe laces. They play a role in numerous physical and biological phenomena, such as the untangling of DNA when it replicates. However, knot theory is also a well-developed branch of pure mathematics.

In his talk, Marc will give an introduction to this theory and will place it in the context of the modern field of topology. This is the branch of mathematics where you are allowed to stretch and deform objects, but not tear them. He will explain how topological techniques can be used to prove some surprising facts about knots. He will also give some problems about knots that mathematicians haven't yet been able to solve.

Marc Lackenby is a Professor of Mathematics in Oxford and a Fellow of St Catherine's College.

5.00pm-6.00pm, Mathematical Institute, Oxford

Please email @email to register.

Watch live:

https://www.facebook.com/OxfordMathematics
https://livestream.com/oxuni/lackenby

The Oxford Mathematics Public Lectures are generously supported by XTX Markets.

Fri, 01 Mar 2019

14:00 - 15:00
L1

Mathematics: the past, present and future - "Polynomials"

Prof Nick Trefethen
Abstract

Polynomials have been at the heart of mathematics for a millennium, yet when it comes to applying them, there are many puzzles and surprises. Among others, our tour will visit Newton, Lagrange, Gauss, Galois, Runge, Bernstein, Clenshaw and Chebfun (with a computer demo).

Fri, 22 Feb 2019

14:00 - 15:00
L1

How we learn

Dr Iro Xenidou-Dervou
Abstract

How do humans process information? What are their strengths and limitations? This crash course in cognitive psychology will provide the background necessary to think realistically about how learning works.

Fri, 15 Feb 2019

14:00 - 15:00
L1

Telling a mathematical story

Dr Vicky Neale and Dr Richard Earl
Abstract

Mathematicians need to talk and writeabout their mathematics.  This includes undergraduates and MSc students, who may be writing a dissertation or project report, preparing a presentation on a summer research project, or preparing for a job interview.  We think that it can be helpful to think of this as a form of story telling, as this can lead to more effective communication.  For a story to be engaging you also need to know your audience.In this session, we'll discuss what we mean by telling a mathematical story, give you some top tips from our experience, and give you a chance to think about how you might put this into practice.  The session will be of relevance to all undergraduates and MSc students, not only those currently writing a dissertation or preparing an oral presentation.

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