Feb 8  Thu  Sarah Whitehouse (Sheffield)  Topology Seminar  
16:00  Homotopy theory of spectral sequences  
Hicks Seminar Room J11  
Abstract: For each r, maps which are quasiisomorphisms on the r page provide a class of weak equivalences on the category of spectral sequences. The talk will cover homotopy theory associated with this setting. We introduce the category of extended spectral sequences and show that this is bicomplete by analysis of a certain presheaf category modelled on discs. We endow the category of extended spectral sequences with various model category structures. One of these has the property that spectral sequences is a homotopically full subcategory and so, by results of Meier, exhibits the category of spectral sequences as a fibrant object in the BarwickKan model structure on relative categories. We also note how the presheaf approach provides some insight into the décalage functor on spectral sequences. This is joint work with Muriel Livernet. 



Feb 22  Thu  Joseph Grant (UEA)  Topology Seminar  
16:00  Frobenius algebra objects in TemperleyLieb categories at roots of unity  
Hicks Seminar Room J11  
Abstract: Frobenius algebras appear in many parts of maths and have nice properties. One can define algebra objects in any monoidal category, and there is a standard definition of when such an algebra object is Frobenius. But this definition is not satisfied by something which we'd like to think of as an algebra object in TemperleyLieb categories at roots of unity. We will explore a more general definition of a Frobenius algebra object which covers this example, and will explore some of its properties. This is joint work with Mathew Pugh. 



Feb 29  Thu  Jack Romo (Leeds)  Topology Seminar  
16:00  
Hicks Seminar Room J11  


Mar 7  Thu  Nadia Mazza (Lancaster)  Topology Seminar  
16:00  Endotrivial modules for finite groups of Lie type  
Hicks Seminar Room J11  
Abstract: Let G be a finite group and k a field of positive characteristic p diving the order of G. An endotrivial kGmodule is a finitely generated kGmodule which is "invertible" in some suitable sense. Since the late 70s, these modules have been intensely studied in modular representation theory. In this talk, we review the essential background on endotrivial modules, and present some results about endotrivial modules for finite groups of Lie type, obtained jointly with Carlson, Grodal and Nakano. 



Mar 21  Thu  Andy Baker (Glasgow)  Topology Seminar  
16:00  
Hicks Seminar Room J11  


Apr 18  Thu  Briony Eldridge (Southampton)  Topology Seminar  
16:00  
Hicks Seminar Room J11  


Apr 25  Thu  Georg Struth (Sheffield)  Topology Seminar  
16:00  
Hicks Seminar Room J11  


May 2  Thu  Ehud Meir (Aberdeen)  Topology Seminar  
16:00  
Hicks Seminar Room J11  


May 23  Thu  Oliver House (Sheffield)  Topology Seminar  
16:00  
Hicks Seminar Room J11  

