# Posts Categorized: math

• geometry, math

## Grothendieck topologies as functors to Top

Posted on by

Either this is horribly wrong, or it must be well-known. So I guess I’m asking for either a rebuttal or a reference. Take a ‘smallish’ category $\mathbf{C}$. By this I mean that for every object $C$ the collection of all maps ending in $C$ must be a set. On this set, let’s call it $y(C)$… Read more »

• books, france, math, personal, stories

## NaNoWriMo (1)

Posted on by

Some weeks ago I did register to be a participant of NaNoWriMo 2016. It’s a belated new-year’s resolution. When PS (pseudonymous sister), always eager to fill a 10 second silence at family dinners, asked (PS) And Lieven, what are your resolutions for 2016? she didn’t really expect an answer (for decades my generic reply has… Read more »

• math

## from chocolate bars to constructivism

Posted on by

A fun way to teach first year students the different methods of proof is to play a game with chocolate bars, Chomp. The players take turns to choose one chocolate block and “eat it”, together with all other blocks that are below it and to its right. There is a catch: the top left block… Read more »

• france, geometry, math, stories

## Grothendieck’s gribouillis (2)

Posted on by

We left the story of Grothendieck’s Lasserre notes early 2015, uncertain whether they would ever be made public. Some things have happened since. Georges Maltsiniotis gave a talk at the Gothendieck conference in Montpellier in june 2015 having as title “Grothendieck’s manuscripts in Lasserre”, raising perhaps even more questions. Philippe Douroux, a journalist at the… Read more »

• france, math, stories

## Map of the Parisian mathematical scene 1933-39

Posted on by

. Michele Audin has written a book on the history of the Julia seminar (hat tip +Chandan Dalawat via Google+). The “Julia Seminar” was organised between 1933 and 1939, on monday afternoons, in the Darboux lecture hall of the Institut Henri Poincare. After good German tradition, the talks were followed by tea, “aimablement servi par… Read more »

• Note to self: check Jack Morava’s arXiv notes on a more regular basis! It started with the G+-post below by +David Roberts: Suddenly I realised I hadn’t checked out Morava‘s “short preprints with ambitious ideas, but no proofs” lately. A couple of years ago I had a brief email exchange with him on the Habiro… Read more »

• math, noncommutative

Posted on by