Publications

A Topological Approach to Scaling in Financial Data

Date: October 2017
Authors: Jean de Carufel, Martin Brooks, Michael Stieber, Paul Britton
E print: https://arxiv.org/pdf/1710.08860.pdf

There is a large body of work, built on tools developed in mathematics and physics, demonstrating that financial market prices exhibit self-similarity at different scales. In this paper, we explore the use of analytical topology to characterize financial price series. While wavelet and Fourier transforms decompose a signal into sets of wavelets and power spectrum respectively, the approach presented herein decomposes a time series into components of its total variation. This property is naturally suited for the analysis of scaling characteristics in fractals.

 

Varilets: Additive Decomposition, Topological Total Variation, and Filtering of Scalar Fields

Date: April 2016
Authors: Martin Brooks
E print: http://arxiv.org/pdf/1503.04867.pdf

Continuous interpolation of real-valued data is characterized by piecewise monotone functions on a compact metric space. Topological total variation of piecewise monotone function f:X->R is a homeomorphism-invariant generalization of 1D total variation. A varlet basis is a collection of piecewise monotone functions { gi |i = 1…n}, called varlets, such that every linear combination ∑aigi has topological total variation ∑|ai|. A varlet transform for f is a varlet basis for which f=∑αigi. Filtered versions of f result from altering the coefficients αi.