The Lord of The Definite Integrals

Math, or at least mostly math…

So, umm, yea…

I still exist, despite not posting for almost a year and a half. Go. Me.

While I still intend to (some day) continue with quandle posts, for the time being I’ll be switching to talking about the work I’m doing this summer (and probably will talk a bit about most of the work I did last summer, which is very tangentially related.)

June 17, 2009 Posted by Geoff | Computer Science, Math, Off Topic | , | No Comments Yet

Kludging an MP3 Bookmark

Suppose you, a run of the mill Linux user, just downloaded a very long mp3 – for example a 10 hour mp3 of Cory Doctorow reading The Hacker Crackdown. Naturally you’re not going listen to this in one sitting; but, you cannot find a media player that implements bookmarking. What do you do?

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February 22, 2008 Posted by Geoff | Computer Science, Off Topic | | 2 Comments

Well-Definededness

In Algebra, we just finished chapter 10 of Gallian. One of the big theorems in the chapter is the First Isomorphism Theorem – and since I’m a lazy typist I’ll call it FIT from now on. (Isomorphism theorems 2 and 3 are left as exercises.) Skipping over what a group is, what a homomorphism is, what the kernel of said homomorphism is, and what normal subgroups and factors groups are (see, FIT talks about all sorts of cool stuff!), FIT says:

Suppose \theta :G \longrightarrow G^\prime is a homomorphism. Then G/\text{ker}\theta \cong G^\prime\theta; moreover, the map \theta : G/\text{ker}\theta \longrightarrow G^\prime\theta by  g\text{ker}\theta \mapsto g\theta is an isomorphism.

One of the points of the proof, since \theta is defined on the cosets of G/\text{ker}\theta by specifying the image of a representative, is whether or not the map \theta is even well defined for some g\text{ker}\theta \in G/\text{ker}\theta. In particular, will taking different representatives of the coset g\text{ker}\theta always have the same image? It turns out that the map is indeed well defined – it’s a rather straightforward argument – but this just brings up another question:

If a map is well defined, does it have the property of well-definededness?

Yay, English!

EDIT: Fixed my accidental interspersing of \varphi for \theta.

February 8, 2008 Posted by Geoff | Algebra, Groups, Math, Off Topic | | No Comments Yet

Introduction

So I suppose I should start with the obligatory “Who the hell are you and why should I read this?” post. My name’s Geoff, I’m currently a junior year (I think… long story that I may or may not tell) undergraduate in Theoretical Math at the University of Akron.

I study math because I legitimately enjoy the subject, hard as that may be to believe if you’re not familiar with upper level mathematics. I also study computer science because I like things like programming, operating systems, and databases. Yes, I run Linux. Beyond that… we’ll see where it goes.

January 4, 2008 Posted by Geoff | Computer Science, Math, Off Topic | | 1 Comment