Homepage of Peter Harremos (Entro-Peter)

Photo of PeterMidg�rdsormen

E-mail: harremoes@ieee.org

Mobile: +45 30 32 41 71

Skype: peterharremoes

Rnne All 1, st.
2860 Sborg
+45 39 56 41 71

Research news

Lattice theory of causation I am working on a larger project where I explore concepts related to cause and effect using lattice theory. I recently published a paper entitled Entropy Inequalities on Lattices where the basic results on the relation between lattices and extreme polymatroid functions is described. I am now working on a paper draft where influence diagrams are described in terms of lattices.

Foundation of quantum theory The paper Entropy on Spin Factors was published recently. It is part of a series of papers related to foundation of quantum theory. At ISIT2017 I gave a talk entitled Information Theory on Spectral Sets. The results strongly indicate that information theory is only possible in mathematical structures that can be represented  on Jordan algebras. There are 5 basic types of Jordan algebras, and density matrices with complex entries is the most important in the sense that quantum information theory is normally represented on this type of algebra. I guess that many results from quantum information theory can be generalized to Jordan algebras. This work follows up on a paper entitled Divergence and Sufficiency for Convex Optimization that I recently published in Entropy.

Tail bounds I published a long paper with various bounds on tail probabilities in terms of the signed log-likelihood function in Kybernetika and it was awarded the best paper in Kybernetika 2016. Although the inequalities are quite sharp, I am sure even sharper inequalities of these types can be obtained. I think the results can be generalized to cover all exponential families with simple variance functions. Even more general inequalities may exist, but at the moment I don't know how to attack the general problem.

Link to my page on Research Gate

Mendeley logo

My Publons profile

ORCID: 0000-0002-0441-6690

List of Publications



My research is centered on information theory. One of my interests is how to use ideas from information theory to derive results in probability theory. Many of the most important reslts in probability theory are convergence theorems, and many of these convergence theorems can be reformulated so that they state that the entropy of a system increases to a maximum or that a divergence converge to a minimum. These ideas are also relevant in the theory of statistical tests. Recently I have formalized a method for deriving Jeffreys prior as the optimal prior using the minimum description length principle.
I am also interested in quantum information theory, and I think that information theory sheds new light on the problems of the foundation of quantum mechanics. In a sense the distinction between matter and information about matter disappear on the quantum level. Combining this idea with group representations should be a key to a better understanding of quantum theory.
I have also worked on the relation between Bayesian networks and irreversibility, and my ultimate goal is to build a bridge between these ideas and information theory. I am working on a new theory where methods from lattice theory are used. I think lattices of functional dependence will provide a more transparent framework to describe causation. Hopefully it will lead to better algorithms for detecting causal relationship, but the most important application might be in our description of quantum systems, where we know that our usual notion of causation break down.

Erdős number = 3

One chain of this length is Paul Erdős -> Vitaly Bergelson -> Daniel Berend -> Peter Harremos.

Editorial work

I am editorial board member of the journals EntropyStats, and Sci. I am newly elected as member of the advisory Board of the journal Sci. I was Editor-in-Chief of  Entropy 2007-2011 and associated editor since2011. This journal was pioneering in open access publishing.

I serve as reviewer of numerous other journals as can be seen from my newly created Publons profile.


ISIPTA 2019 This conference will be held in Ghent, Belgium 3-6 July 2019. I have submitted one paper for this conference.
ISIT 2019 6-12 July 2019. This year it will be held in Paris. I submitted two papers to this conference.
WPI 2019 I was invited speaker at this conference. Title of talk TBA.
ITW 2019 will be held in Visby, Sweden 25-28 August 2019. Submission deadline is April 1st.
From Physics to Information Sciences and Geometry May 14-16 in Barcelona, Catalonia/Spain.
International Z�rich Seminar on Information and Communication (IZS) 2018  21-23/2 I gave an invited talk entitled Horizont independent MDL.


I have made a BibTeX file with a lot of items related to information theory.

Information Theory Society I am seniir member of IEEE and the Information Theory Society is a part of this organization. The page has a lot of useful links related to information theory.
Danish Climbing Federation I am active climber and has served as president of this organization.
Entropy The Journal that I was Editor-in-Chief for. At the moment I serve as associated editor.
Ideal scientific equipment A less useful link.
IEEE Transactions on Information Theory I was associated editor of this journal covering Information Theory and Statistics.
Minimum Description Length on the web This pages is devoted to MDL and its applications. I contains links to articles and people working in the field.
Teaching portfolio Here I have collected various material relevant for my teaching activities.
The cross entropy method


Here are links to some of my favorite software.

Dropbox Very convenient for storing and sharing documents.
GeoGebra Software to create mathematical figures. It can output an image as pgf code.
JabRef Program that helps you manage your BibTeX database.
Online LaTeX diff tool You can send two files with LaTeX code to this cite and you will get one PDF file back with colormarking of all changes.
LyX User friendly graphical user interface to LaTeX.
PDF-XChange Great for annotating PDF documents. The free version is good and the prof. version is even better.
R Great for statistical programming. With the module Sweave R-code can be embedded directly into LaTeX documents.
TikzEdt Editor for TikZ/pgf code.


Here are links to some persons that I use to collaborate with.

Andrew Barron
Christophe Vignat
Flemming Topse
Gabor Tusnady
Ioannis Kontoyiannis
Laszl Gyrfi
Łukasz Debowski
Oliver Johnson
Peter Grnwald
Tim van Erven