Submitting lecture purposal to conferences. (lecture about a thesis) I wish to consult with you about something: I have recently given a lecture about my master's Thesis in a local conference organized by my advisor. The subject had a lot to do with algebraic geometry and tropical geometry.
I would like very much to try and submit that very same lecture to other conferences. No need to say, algebraic geometry is a vast field, and the title of such conferences is very specific, and not every conference of algebraic geometry is suitable for my lecture. given all that, my question is: under which circumstances will it be appropriate to submit my lecture?
Another question, on the practical side, If I can't find a decent "call for papers", is it still appropriate to propose my lecture to the conference organizer via an E-mail?
Is it OK if my paper has not yet been published except for the arXiv?
On a side note, how do one finds out about conferences and 'calls for papers'?
Thank you.
 A: Unlike the other sciences (especially computer science), there really isn't much of a tradition in mathematics of a "call for papers" for conferences.  For the most part, all of the lectures in a typical math conference are "invited lectures"; the organizers of the conference choose a list of people they would be interested in hearing speak and invite them to give any talk they want to give.
In the same way, if a conference decides to publish proceedings (and most do not!), then generally they invite everyone who attended to submit a paper.  These papers often do not correspond to the talks!  Usually people want to speak about their best recent work (which they will want to submit to a journal); conference proceedings are usually used for either survey papers or papers that the writer judges not strong enough for a good journal.  For the most part, these are refereed in the traditional manner.  I personally do not list them in a separate section of my cv; I regard them as the same as ordinary papers.  This is again very different from other subjects!
The conference webpage will indicate if they are interested in having people who are not invited speakers submit abstracts for potential talks.  In this situation, it is fine to propose any talk you want to give, whether or not the work in question has been published (or even written!) or not.
As Gerry said in the comments, I recommend speaking to your advisor about this.
