Fri, 17 Jun 2016

11:00 - 12:00
C2

Period rings II

Constantin Ardakov
(Oxford)
Abstract

Continuation of the last talk.

Fri, 10 Jun 2016

11:00 - 12:00
C2

Period rings

K. Ardakov
(Oxford)
Abstract

This talk will give a description of the period ring B_dR of Fontaine, which uses de Rham algebra computations. 

This talk is part of the workshop on Beilinson's approach to p-adic Hodge  theory.

Fri, 03 Jun 2016

11:00 - 12:00
C2

The de Rham algebra of a point in affine space

Damian Rössler
(Oxford)
Abstract

Following the notes and an article of B. Bhatt, we shall compute the de Rham algebra of the immersion of the zero-section of affine space over Z/p^nZ.

This talk is part of the workshop on Beilinson's approach to p-adic Hodge theory.

Fri, 27 May 2016

11:00 - 12:00
C2

The de Rham algebra

Kevin McGerty
(Oxford)
Abstract

This talk will describe the basic properties of the de Rham algebra, which is a generalisation of the de Rham algebra over smooth schemes, which was introduced by L. Illusie in his monograph 'Complexe cotangent et déformations'.

Fri, 20 May 2016

11:00 - 12:00
C2

Universal thickening of C_p

Damian Rössler
((Oxford University))
Abstract

This is the 4th talk of the study group on Beilinson's approach to p-adic Hodge theory, following the notes of Szamuley and Zabradi.

I shall finish the computation of the module of differentials of the ring of integers of the algebraic closure of Q_p and describe a universal thickening of C_p.

I shall also quickly introduce the derived de Rham algebra. Kevin McGerty will give a talk on the derived de Rham algebra in W5 or W6.

Wed, 08 Jun 2016
16:00
C2

Intensional Partial Metric Spaces

Steve Matthews
(Warwick)
Abstract

Partial metric spaces generalise metric spaces by allowing self-distance
to be a non-negative number. Originally motivated by the goal to
reconcile metric space topology with the logic of computable functions
and Dana Scott's innovative theory of topological domains they are now
too rigid a form of mathematics to be of use in modelling contemporary
applications software (aka 'Apps') which is increasingly concurrent,
pragmatic, interactive, rapidly changing, and inconsistent in nature.
This talks aims to further develop partial metric spaces in order to
catch up with the modern computer science of 'Apps'. Our illustrative
working example is that of the 'Lucid' programming language,and it's
temporal generalisation using Wadge's 'hiaton'.

Wed, 18 May 2016
16:00
C2

Locally compact normal spaces: omega_1-compactness and sigma-countable compactness

Peter Nyikos
(South Carolina)
Abstract

ABSTRACT: A space of countable extent, also called an omega_1-compact space, is one in which every closed discrete subspace is countable.  The axiom used in the following theorem is consistent if it is consistent that there is a supercompact cardinal.

Theorem 1  The LCT axiom implies that every hereditarily normal, omega_1-compact space
is sigma-countably compact,  i.e., the union of countably many countably compact subspaces.

Even for the specialized subclass of monotonically normal spaces, this is only a consistency result:

Theorem 2   If club, then there exists a locally compact, omega_1-compact monotonically
normal space that is not sigma-countably compact.

These two results together are unusual in that most independence results on
monotonically normal spaces depend on whether Souslin's Hypothesis (SH) is true,
and do not involve large cardinal axioms. Here, it is not known whether either
SH or its negation affect either direction in this independence result.

The following unsolved problem is also discussed:

Problem  Is there a ZFC example of a locally compact, omega_1-compact space
of cardinality aleph_1 that is not sigma-countably compact?

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