Entropy and Diversity

An undergraduate seminar during the fall of 2021.

How might one go about designing a useful measure of diversity for, say, an ecological system? One approach is to begin with a set of desiderata, a list of properties that any good measure of diversity ought to satisfy, and go about constructing all measures that satisfy these properties. With enough properties, it may be the case that the measure in question is essentially uniquely determined.

This is the approach of our text, in which we will discover that any measure of diversity satisfying a set of reasonable assumptions coming from ecological principles is amongst a family of well-known diversity measures, the Hill numbers. This in turn is a simple transformation of another well-known measure of variety, entropy. As such, I hope our journey through this book will give many different perspectives on the notion of entropy, and related concepts.

Prerequisites, Format, Expectations, etc.

Each participant will give 2 talks over the course of the semester, during which I hope one enjoys some interesting mathematics, as well as meditates on the art of presenting and talking about mathematics. During the rest of the semester, I hope that those that are not presenting will help form a lively and friendly seminar environment, one in which all participants can feel comfortable to discuss and learn in.

References

The primary reference for this seminar is the book

Some related papers that might be fun to look at include:

Schedule

We meet Monday and Wednesdays from 10 AM to 11 AM in Mathematics Room 622.

09/09
Organization.
09/20
Raymond Cheng
Introduction. Cauchy's Functional Equation.
09/23
Joe Scerbo
Finite probability distributions and Shannon's Entropy.
09/27
Mirah Shi
The Chain Rule and Faddeev's Classification Theorem
09/30
Madisen Siegel
Entropy and diversity in ecology
10/04
Thomas Lim
Shannon entropy and information
10/06
Hallie Moseley
\(q\)-logarithmic entropies
10/11
Feitong Qiao
Information loss
10/13
Feitong Qiao
Characterization of information loss
10/18
Hirotaka Goto
Similarity-sensitive diversity
10/20
Sloane Clifton
Entropy modulo a prime
10/25
Yiqi Wang
Power means
10/27
Maryam Abdool
Operads and their algebras
11/01
No Seminar
Go vote!
11/03
No Seminar
Raymond is away
11/08
Leo Lo
Relative entropy in geometry
11/10
Leah Teller
Rényi entropies and Hill numbers
11/15
Claire Lin
Entropy and financial applications
11/17
Raymond Cheng
Magnitude
11/22
Aya Batoul Tazi
Physical entropy
11/24
No Seminar
Happy Thanksgiving!
11/29
Hirotaka Goto and Yiqi
Rao's Entroy
12/01
Hallie Moseley and Madisen Siegel
Mutual information and metacommunities
12/06
Mirah Shi
Maximizing diversity on graphs
12/08
Thomas Lim and Maryam Abdool
Entropy in decision trees; Noisy communications
12/13
Tiber Seireeni
Total characterization of the Hill numbers