Chris Freiling

Axioms of symmetry: Throwing darts at the real number line

We will give a simple philosophical “proof” of the negation of Cantors continuum hypothesis (CH). (A formal proof for or against CH from the axioms of ZFC is impossible; see Cohen [1].) We will assume the axioms of ZFC together with intuitively clear axioms which are based on some intuition of Stuart Davidson and an old theorem of Sierpinski and are justified by the symmetry in a thought experiment throwing darts at the real number line. We will in fact show why there must be an infinity of cardinalities between the integers and the reals. We will also show why Martins Axiom must be false, and we will prove the extension of Fubinis Theorem for Lebesgue measure where joint measurability is not assumed. Following the philosophy—if you reject CH you are only two steps away from rejecting the axiom of choice (AC)—we will point out along the way some extensions of our intuition which contradict AC.

Rectangling a rectangle

AbstractWe show that the following are equivalent: (i) A rectangle of eccentricityv can be tiled using rectangles of eccentricityu. (ii) There is a rational function with rational coefficients,Q(z), such thatv =Q(u) andQ maps each of the half-planes {z ¦ Re(z) < 0} and {z ¦ Re(z) > 0 into itself, (iii) There is an odd rational function with rational coefficients,Q(z), such thatv = Q(u) and all roots ofv = Q(z) have a positive real part. All rectangles in this article have sides parallel to the coordinate axes and all tilings are finite. We letR(x, y) denote a rectangle with basex and heighty. In 1903 Dehn [1 ] proved his famous result thatR(x, y) can be tiled by squares if and only ify/x is a rational number. Dehn actually proved the following result. (See [4] for a generalization to tilings using triangles.)

Generalizations of the wave equation

The main result of this paper is a generalization of the property that, for smooth u, u xy = 0 implies (*) u(x, y) = a(x) + b(y). Any function having generalized unsymmetric mixed partial derivative identically zero is of the form (*). There is a function with generalized symmetric mixed partial derivative identically zero not of the form (*), but (*) does follow here with the additional assumption of continuity. These results connect to the theory of uniqueness for multiple trigbnometric series. For example, a double trigonometric series is the L 2 generalized symmetric mixed partial derivative of its formal (x, y)-integral

A mean value theorem for generalized Riemann derivatives

Functional differences that lead to generalized Riemann derivatives were studied by Ash and Jones in (1987). They gave a partial answer as to when these differences satisfy an analog of the Mean Value Theorem. Here we give a complete classification.

How to Compute Antiderivatives

The roots of this problem go back to the beginnings of calculus and it is even sometimes called “Newton’s problem”. Historically, it has played a major role in the development of the theory of the integral. For example, it was Lebesgue’s primary motivation behind his theory of measure and integration. Indeed, the Lebesgue integral solves the primitive problem for the important special case when f(x) is bounded. Yet, as Lebesgue noted with apparent regret, there are very simple derivatives (e.g., the derivative of F (0) = 0, F (x) = x sin(1/x) for x 6= 0) which cannot be inverted using his integral. The general problem of the primitive was finally solved in 1912 by A. Denjoy. But his integration process was more complicated than that of Lebesgue. Denjoy’s basic idea was to first calculate the definite integral R b

The Change of Base Formula for Logarithms

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