Halley: The next iterate is the zero of the Mobius transformation that osculates the level set of |f| at z_k.
the xy-plane, and ·
the plane tangent to the graph of F at (x_k,y_k,F(x_k,y_k)).
The Rook on the Half-Chessboard, or How Not to Diagonalize a Matrix
by Kiran S. Kedlaya and Lenhard L. Ng
We study a simple-looking family of matrices whose eigenvalues appear equally innocuous. The diagonalization of these matrices is not quite so innocuous; we present two approaches, one of which requires a four-variable combinatorial identity with a somewhat roundabout proof. We then apply this result to explore two related random walks, summarized as "the rook on the half-chessboard." Given an n-by-n chessboard from which all squares above (but not including) the northwest-southeast diagonal have been removed, a rook moves with probability 1/2 to some square in its row, and with probability 1/2 to some square in its column. We determine the speeds at which this walk, and a related, more efficient walk, become random.
The Last Round of Betting in Poker
by Jack Cassidy
Mathematical analyses of poker usually assume an unrealistic set of circumstances that never occur in real play. Chief among these is that all players have equal hands going into the final draw.
This paper assumes generalized, unequal hand distributions for two players in the final round of betting. We develop six simple equations for optimal strategies when raising is not allowed, then look at how things change when raising is allowed.
We apply the equations to a sample hand of Seven Card Stud, and give pointers on how to apply the optimal strategies to real-life poker games.
Applications of the Universal Subjectivity of the Cantor Set
by Yoav Benyamini
Every compact metric space is a continuous image of the Cantor set, i.e., for each compact metric space K there is a continuous map from the Cantor set onto K.
This classical theorem of Alexandroff and Hausdorff can heuristically be rephrased as saying that "compact sets of data can be continuously encoded by the Cantor set". This principle is a very powerful tool that can be applied to solve a variety of unrelated problems in topology, geometry, and analysis. In this article we present several such applications. The following two examples are typical.
(i) (R. Grzaslewicz) For each d 1 there is a compact convex set B in R^(d+2) with the property that each compact convex subset of the d-dimensional unit cube is congruent to a face of B.
(ii) There is a real-valued, bounded, and continuous function f on the real line R with the property that for each doubly infinite sequence (y_n)_(n \ in Z) of real numbers satisfying |y_n |£ 1 for all n, there is a point t \in Rsuch that y_n = f(t + n) for all n \in Z.
The Group Z_2 x Z_n and Regular Polygonal Paths
by Apostolos Thoma
A Quick Cayley-Hamilton
by Busiso P. Chisala
The Probability of a Tie in an n-Game Match
by J. Marshall Ash
The Converse of the Mean Value Theorem May Fail Generically
by J. M. Borwein and Xianfu Wang
A Trio of Triangular Number Theorems
by John A. Ewell
THE EVOLUTION OF...
by John Stillwell
PROBLEMS AND SOLUTIONS
By Keith Devlin.
Reviewed by Dan Schnabel
Fourier Analysis and Boundary Value Problems
By Enrique A. González-Velasco.
Reviewed by Jeffrey Nunemacher
Fair Division: From Cake-Cutting to Dispute Resolution
By Steven J. Brams and Alan D. Taylor.
Reviewed by William F. Lucas