Physics of Risk

Beta prime distribution

Aleksejus Kononovicius — Tue, 02 Jun 2026 08:00:00 +0300

Have you heard of the beta prime distribution before? Until recently, I hadn't either. My colleague, Rytis Kazakevičius, recently surprised me by pointing out that the distribution we have been repeatedly encountering in nonlinear transformations of the noisy voter model has actually a proper name. It is known as the beta prime distribution. And our history with this distribution, goes back much further.

MinutePhysics: Problem with Newcomb's paradox

Aleksejus Kononovicius — Tue, 19 May 2026 08:00:00 +0300

Recently, Veritasium has posted a video on Newcomb's paradox. This paradox is based on a decision-making problem. Namely, you are presented with two boxes. Box A is transparent and contains a small amount of money, while Box B is opaque. Box B might contain a large amount of money or be empty. Its contents are decided ahead of time by a machine, which has perfect prediction record. If the machine predicts that you will take only Box B, it will put large amount of money inside it. Otherwise, it will keep Box B empty. So, will you take only Box B (and believe in predictor accuracy) or will you take both boxes (and believe in game theory)? For more details on the paradox and its solutions watch the video below.

After watching the video above I wasn't particularly fond of the paradox. Mostly because the paradox seemed to be artificially contrived. After watching minute physics (previously known as One Minute Physics) video I still feel the same way, but surprisingly this paradox prompts us to consider the nature of our own reality. I encourage you to watch it as well.

I especially liked the part about random 5 year old falsely achieving incredible accuracy.

The defining property of stable distributions

Aleksejus Kononovicius — Tue, 12 May 2026 08:00:00 +0300

Our group, along with a few students, has been reading statistics handbook and refreshing our understanding of the basic statistics. I was given to cover a chapter about the central limit theorem, which reminded me that I had already given a similar presentation while being PhD student myself. While diving into the topic, I have noticed a couple things, which are usually glanced over in a typical statistics handbook. In the final post of this series, let me put an emphasis on the defining property of any stable distribution.

Summation of infinitely divisible random variates

Aleksejus Kononovicius — Tue, 28 Apr 2026 08:00:00 +0300

Our group, along with a few students, has been reading statistics handbook and refreshing our understanding of the basic statistics. Some time ago, I was given to cover a chapter about the central limit theorem, which reminded me that I had already given a similar presentation while being PhD student myself. While diving into the topic, I have noticed a couple things, which are usually glanced over in a typical statistics handbook. Let me share them with you.

This time we explore infinite divisibility. Our previous mathematical explorations of the stable distributions topic have relied on this property, because it simplifies many of the analytical derivations. But there are distributions, which are infinitely divisible but not stable. This time let us take a look at sums of Gamma distributed random variates.

A. Chadha: Cauchy 101

Aleksejus Kononovicius — Tue, 21 Apr 2026 08:00:00 +0300

Over the last few posts we have taken a look at the Cauchy distribution, which apparently has undefined mean and variance. You will find a useful review and some novel personal insights from an enthusiastic student Ananya Chadha in the video below.

MSCA hosting invitation (2026)

Aleksejus Kononovicius — Thu, 16 Apr 2026 08:00:00 +0300

If you are interested in complex systems, physical modeling of opinion dynamics or financial markets, then you might be interested in my invitation to host MSCA postdoctoral fellows.

More information on the Euraxess website »

What happens if you sum Cauchy random variates?

Aleksejus Kononovicius — Tue, 14 Apr 2026 08:00:00 +0300

In the previous post we have taken a look at a distribution whose mean and variance are undefined. We know that the central limit theorem holds only if mean and variance of the sample distribution are defined and finite. So what happens if we sum Cauchy random variates?

Cauchy distribution

Aleksejus Kononovicius — Tue, 31 Mar 2026 08:00:00 +0300

In the previous post we have talked about a peculiar result in statistics - that an average of well-behaved random variates (those that come from distributions with finite mean and variance) is distributed according to the normal (Gaussian) distribution. But what happens if the variates are not well-behaved? Accompanying video briefly mentions Cauchy distribution, as a distribution describing random variates, which are not well-behaved. Let us take a look at it!

Open call for PhD students (2026 admission)

Aleksejus Kononovicius — Tue, 24 Mar 2026 08:00:00 +0200

Are you interested in complex systems, opinion dynamics, or the voter model? Do you have a Master's degree in Physics or Mathematics and a good grasp of statistics and numerical simulation? Would you like to work together with me as your PhD supervisor? If so, apply for a PhD studies at the Institute of Theoretical Physics and Astronomy (part of the Faculty of Physics at Vilnius University). Description of the PhD topic I am offering is provided below.

StatQuest: Central limit theorem

Aleksejus Kononovicius — Tue, 17 Mar 2026 08:00:00 +0200

We have already previously shared a video about the central limit theorem, but recently I have found another neat explanation by StatQuest. I would like to invite you to watch it.