Categories
Math

Teaching Math Can Lead to New Research

I have recently found a curious phenomenon in which teaching math can actually lead to new mathematical ideas, and as a result possibly new research. In this post, I’ll discuss some ways this can happen.

Categories
Math

Non-Standard Axioms for Various Math Structures 2

This is part of a series in which we investigate non-standard axiomatizations of various math structures. The previous post in the series was concerned with single equational axioms for equational classes. In this post, we are inspired by a particularly elegant characterization of (abstract) Boolean algebras, and we consider whether similar “Boolean algebra-like” characterizations can be given for other common structures.

Categories
Math

Non-Standard Axioms for Various Math Structures

This is the first post in a series. This started as an investigation of various non-standard axiomatizations of common structures, but soon the posts ended up focusing on a particular such kind of axiomatization. Thus, this title is misleading (and anyway, it seems too broad for a single series.)

Categories
Math

Facts About Field Extensions

This is a list of definitions and theorems concerning field extensions, that I’m compiling for my learning. Throughout, let K be a field.

Categories
Math

On Renaming Universal Algebra

Especially in comparatively recent times, researchers in the subject of universal algebra have sought to replace that name, leading people to choose an alternative term instead. In this post, I discuss my thoughts on this matter.

Categories
Math

Algebraic Structures Applicable to All Sets

This exploration is inspired by the fact that, given the Axiom of Choice, any set can be given a group structure. (Fine print: throughout the rest of this post, we assume all sets are nonempty.) In fact, these two statements are equivalent. Questions about similar statements have popped up in other contexts; for example, in Topology as an Algebraic Structure, the question arises as to whether any infinite set can be given a field structure. (Clearly, not every finite set can be given a field structure, since we have the classification of finite fields.)

Categories
Math

Construction of the Reals from Decimals

In typical real analysis classes, the presentation of real numbers that is generally given in schools (starting from rationals) is considered insufficiently rigorous, and replaced by a construction involving Dedekind cuts. However, in this post, we investigate a formalization that derives directly from the presentation given in schools — specifically, using decimals — and study its equivalence to the Dedekind cut formulation.

Categories
Math

Characteristic of a Monoid

In ring theory, the characteristic is defined as the min n such that n1 = 0, or 0 if no such n exists; judging from https://en.wikipedia.org/wiki/Characteristic_(algebra), it seems that no concept of characteristic has been considered for structures more general than rings. Here, we generalize the concept to any monoid M.

Categories
Math

Archimedes and the Area of a Circle

In this post, we claim that the method of exhaustion developed by Archimedes to calculate the area of a circle is in fact sufficiently rigorous.

Categories
Math

Sine Angle Addition Functional Equation 2

In this post, we continue the discussion from this post, where we investigate the sine angle addition functional equation

\displaystyle f(a + b) = f(a)f\left( \frac{\pi}{2} - b \right) + f\left( \frac{\pi}{2} - a \right)f(b).