About Me

Sebastian Zajac earned his PhD in Physics at the University of Silesia in Katowice. He is currently a theoretical physicist, an assistant professor and an associate dean for infrastructure at the Faculty of Mathematics and Natural Studies, Cardinal Stefan Wyszynski University in Warsaw (Poland).
He is a American Physical Society member. The focus of his research is mathematical physics, statistics and data analysis, in particular phenomenology of neutrino physics and geometry, topology and Category Theory in Quantum Mechanics and Quantum Field Theory. His latest publications center around the flavour problem in the field of neutrino physics. With prof. Piotr Sulkowski they are trying to characterize RNA and protein structures by their topological characteristics called genus.


Cardinal Stefan Wyszynski University
Faculty of Mathematics
and Natural Studies
ul. Woycickiego 1/3
01-938 Warsaw, Poland



University of Silesia in Katowice

Doctor of Philosophy 17.09.2013

Advisor: prof. dr hab. Marek Zralek
Accelerator neutrino oscillations and their non-standard interactions (PL). View

Master of Science 27.06.2007

Advisor: dr hab. Jerzy Król
Some geometrical and topological methods in classical and quantum field theory.(PL) View

Bechelor of Science 27.06.2005

Advisor: dr hab. Jacek Syska
Time Series analysis with ARMA and ARIMA processes. Application in SAS. (PL) View

Music School in Rybnik, I and II degree

Musician 2004

Advisor: Franciszek Prus
Accordeon class.


Lepton Masses and Mixing in Two-Higgs-Doublet Model

P.Chaber, B. Dziewit, J. Holeczek, M. Richter, M. Zrałek, S.Z.
to appear

In frame of the two-Higgs Doublet Model we try to find some discrete, non-abelian flavour symmetry, which could explain masses and mixing matrix elements for leptons. Unlike to the Standard Model currently the flavour symmetry need not to be broken. With the GAP program we investigate all finite groups up to 1025 order that have 2 and 3-dimensional irreducible, faithful representations. Up to such order there is no group, for which it is possible to select free model parameters in order to match, in satisfactory way, the masses of charged leptons, masses of neutrinos, and PMNS mixing matrix elements.

Genus trace for biomolecules

S.Z., C. Geary, E.A. Andersen, P.Dabrowski-Tumanski, J.Sulkowska, P.Sulkowski
to appear

We introduce the notion of the genus trace, which describes dependence of genus on the choice of a subchain of a given backbone chain. We find that the genus trace encodes interesting physical and biological information about a given biomolecule and its three dimensional structural complexity. We illustrate this statement by showing how the genus trace captures properties of various types of base pairs in RNA, enables to identify a domain structure of a ribosome and of proteins, etc. We find that the shape of the genus trace can detect cooperative folding inside multidomain protein. We also conduct a survey of all published RNA structures better than 3 A resolution in the PDB database, and find that natural structural RNAs have a roughly linear relationship in genus complexity per unit length.

The discrete family symmetries as the possible solution to the flavour problem

B.Dziewit, J.Holeczek, M.Richter, M.Zralek, S.Z.
Physics of Atomic Nuclei Vol. 80, No. 4 (09.2017)

In order to explain the fermions masses and mixing parameters appearing in the lepton sector of the Standard Model, one proposes the extension of its symmetry. A discrete, non-abelian subgroup of U(3) is added to the gauge group SU(3) CxSU(2) LxU(1) Y . Apart from that, one assumes the existence of one extra Higgs doublet. This article focuses mainly on the mathematical theorems and computational techniques which brought us to the results. arXiv preprint

Texture zeros in neutrino mass matrix

B.Dziewit, J.Holeczek, M.Richter, M.Zralek, S.Z.
Physics of Atomic Nuclei Vol. 80, No. 2 (07.2017)

The Standard Model does not explain the hierarchy problem. Before the discovery of nonzero lepton mixing angle theta 13 high hopes in explanation of the shape of the lepton mixing matrix were combined with non-Abelian symmetries. Nowadays, assuming one Higgs doublet, it is unlikely that this is still valid. Texture zeroes, that are combined with abelian symmetries, are intensively studied. The neutrino mass matrix is a natural way to study such symmetries.
arXiv preprint

The Flavour Problem and the Family Symmetry Beyond the Standard Model

B.Dziewit, J.Holeczek, M.Richter, M.Zralek, S.Z.
Acta Physica Polonica B46 (2015)

In the framework of a two Higgs doublet model, we try to explain lepton masses and mixing matrix elements assuming that neutrinos are Dirac particles. Discrete family symmetry groups, which are subgroups of U(3) up to the order of 1025 are considered. Like in the Standard Model with one Higgs doublet, we found that discrete family symmetries do not give satisfactory answer to these basic questions in the flavour problem.

Attempts at Explaining Neutrino Masses and Mixings Using Finite Horizontal Symmetry Groups

B.Dziewit, M.Zralek, S.Z.
Acta Physica Polonica B44 (2013)

A brief discussion about the current status of the search for the possible finite symmetry of a leptonic mass matrix is presented. Possible extensions of the models of leptons that can describe the masses and mixing elements are discussed.

Majorana neutrino mass matrix with CP symmetry breaking

B.Dziewit, M.Zralek, S.Z.
Acta Physica Polonica B42 (2011)

From the new existing data with not vanishing θ13 mixing angle we determine the possible shape of the Majorana neutrino mass matrix. We assume that CP symmetry is broken and all Dirac and Majorana phases are taken into account. Two possible approaches “bottom–up” and “top–down” are presented. The problem of unphysical phases is examined in detail.

The method of the likelihood and the Fisher information in the construction of physical models.

E.W.Piotrowski, J.Sładkowski, J.Syska, S.Z.
Physica Status Solidi B, 246 (2009)

The subjects of the paper are the likelihood method (LM) and the expected Fisher information (FI) considered from the point od view of the construction of the physical models which originate in the statistical description of phenomena. The master equation case and structural information principle are derived. Then, the phenomenological description of the information transfer is presented. The extreme physical information (EPI) method is reviewed. As if marginal, the statistical interpretation of the amplitude of the system is given. The formalism developed in this paper would be also applied in quantum information processing and quantum game theory.

Neutrino Oscillations in the case of general interactions

J.Syska, M.Zralek, S.Z.
Acta Physica Polonica B38 (2009)

The process of the neutrino production, oscillation in the vacuum or in matter, and detection in the case of interactions which are beyond the Standard Model is considered. Neutrino states are described by the density matrix. The final neutrino production rate does not factorize. The known Maki–Nakagawa–Sakata neutrino states and the factorized production rate are recovered in the vSM regime.

Work experience

Data Analysis Expert

AMA Institute, Warsaw 10.2017

Associate Dean for Infrastructure

UKSW WMP. SNŚ Warsaw 09.2016


Warsaw School of Economics, Warsaw 02.2016

Assistant Professor

UKSW WMP.SNS, Warsaw 09.2015

Junior Front End Developer

Maxymiser Oracle, Warsaw 11.2015-02.2016

NCN Opus Grant - neutrino physics

University of Silesia, Katowice 04.2014-04.2018


UKSW WMP.SNS, Warsaw 10.2013-09.2015

Postdoc - On topology, interacting RNA and quantum physics

Warsaw University, Warsaw 09.2013-09.2014

Lecturer - Webpage programming in PHP and JS

GoWork, Warsaw 07.2013-01.2015

Statistical Analyst

Biostat, Rybnik 11.2011-01.2012

Software tester SI WCPR system

Wasko, Gliwice 07.2011-09.2011


  • Data processing in SAS: part I (SAS 2017)
  • Data processing in SAS: macro language (SAS 2017)
  • Introduction to Machine Learning with Python (Sages 2017)
  • BigData Analysis with Apache Spark (ESSAM-ICM 2016)
  • Designing and creating OLAP cubes (SAS 2016)
  • Business analysis with SAS Visual Analytics (SGH, SAS 2016)
  • Introduction to Big Data and Apache Hadoop (Sages 2014)


  • Prof. Andrzej Wysmołek. Grafen i magia dwuwymiarowych kryształów
    Wydział Fizyki, ul. Pasteura 5, Warsaw,
    March 20, 2018, 18:00.

    Zainteresowania naukowe prof. Wysmołka związane są głównie z badaniami właściwości optycznych półprzewodników oraz nanostruktur półprzewodnikowych. Jego ostatnie projekty badawcze dotyczyły grafenu oraz jego pochodnych, a w szczególności wykorzystania grafenu jako elementu czujnika przepływu cieczy. Aktualnie zajmuje się badaniami układów hybrydowych grafenu z dichalkogenkami metali przejściowych oraz heksagonalnym azotku boru. Takie struktury warstwowe, przypominające klocki Lego w nanoskali, mogą dostarczyć zupełnie nowych rozwiązań w nanotechnologii.

    Category Theory
  • Neutrino 2018
    XXVIII International Conference on Neutrino Physics and Astrophysics
    June, 4-9, Heidelberg, Germany

    The biennial conference focuses on the current status of neutrino physics, its interplay with astronomy and cosmology and the future prospects of these fields. It is organised by the Max-Planck-Institut für Kernphysik and the Karlsruhe Institute of Technology. The programme consists of invited plenary talks and contributed poster presentations. Several satellite events take place in the days before and after the conference.

    Neutrino physics
  • String-Pheno 2018
    Faculty of Physics, University of Warsaw, July 2-6, 2018.

    Phenomenological aspects of string theory have moved to the forefront of research efforts in the theoretical high energy physics community. This conference aims at bringing together top researchers in the field to present and discuss recent breakthroughs bridging fundamental theory and its implications for particle physics and cosmology. A special emphasis will be placed on innovative mathematical techniques and an effort will be made to include a number of leading mathematicians and mathematical physicists. We are particularly keen to encourage young researchers and will attempt to feature their work prominently at this conference.

    Category Theory
  • 2018 Summer Conference on Topology and its Applications
    Hosted by Western Kentucky University,
    July 17-20, 2018, Bowling Green, KY

    Western Kentucky University will host the 33rd Summer Conference in Topology and its Applications from the morning of Tuesday, July 17, 2018 to Friday, July 20th, 2018. Western Kentucky University is in Bowling Green, Kentucky. The main meeting venue will be Snell Hall, at the northeast end of campus. In addition to the traditional areas usually represented, the conference will include two sessions on applications of topology in the physical sciences. The significance of the interplay between topology and physical sciences was highlighted in the awarding of the 2016 Nobel Prize in Physics to three researchers using topological methods. We are pleased to announce that 2016 Nobel Laureate J. Michael Kosterlitz will deliver a keynote address.

    Topology, Category Theory