## General

 I am a postdoctoral researcher in the Browning Group at the Institute for science and Technology Austria. Before I was a Ph.D. candidate at Leiden University under the supervision of dr. Martin Bright. My research is on arithmetic geometry as I apply geometric techniques to study questions in number theory. I am for example interested in local to global principles such as the Hasse principle and several forms of approximation to both rational and integral points, obstructions to these principles (the Brauer–Manin obstruction, to name one), the counting of points of bounded height, but also effective techniques for points on curves and surfaces. I am fascinated by the endless geometric techniques one can use to study some obvious and seemingly simple questions in number theory. Contact: Julian Lyczak jlyczak (at) ist.ac.at IST Austria Am Campus 1 A – 3400 Klosterneuburg

## Writings

Scientific articles:
Theses:
Here you can find a list of errata of the following notes:
Other people's scientific articles with a (minor) contribution from me:
Miscellaneous:
The "Vakidioot" is the monthly magazine of A-Eskwadraat, the study association for mathematics in Utrecht. "Euclides" is a magazine for high school mathematics teachers. "Pythagoras" is a two-monthly magazine for high school students.

## Code

Code used for the paper "Order 5 Brauer–Manin obstructions to the integral Hasse principle on log K3 surfaces".
• Magma code for the example treated in Section 3 and 4.
• Magma code for the example treated in Section 5.
Code used for my Ph.D. thesis "Arithmetic of affine del Pezzo surfaces".
• Magma code to compute models of del Pezzo surfaces of degree 5 with a specific action of Galois on the ten lines. This document also helps with the computation of the Brauer–Manin obstruction coming from the algebraic Brauer group on the complement of an effective anticanonical divisor. The algebraic Brauer group of such a log K3 surfaces is cyclic of order 5.
Code used for the paper "A uniform bound on the Brauer groups of certain log K3 surfaces".
• Magma code to compute the subgroups of the finite automorphism group of the Picard group of del Pezzo surfaces.
• Magma code to compare the first cohomology groups of subgroups of the Weyl group acting on two free $$\mathbb Z$$-modules. This is used to compare the algebraic Brauer group of a log K3 surface with an irreducible ample anticanonical bundle, to the Brauer group of the corresponding del Pezzo surface.

## Talks

Autumn 2020
Spring 2020
Autumn 2019
Spring 2019:
Spring 2018:
Autumn 2017:
• Explicit Brauer–Manin obstructions of order 5
At the DIAMANT symposium in Breukelen, The Netherlands.
• Why your piano is never in tune!
A lunch lecture organized by De Leidsche Flesch in Leiden.
Spring 2017:
Spring 2016:
Spring 2015:
Older talks (at the University of Utrecht):

## Seminars, conferences etc.

Upcoming:
Current:
Ongoing: Autumn 2019
Spring 2019
Continuous seminars and colloquia at Leiden and in The Netherlands I attended:
Autumn 2018:
Autumn 2018:
Spring 2018:
Autumn 2017:
Spring 2017:
Autumn 2016:
Spring 2016:
Autumn 2015:
Spring 2015:
Older seminars (at the University of Utrecht):

## Teaching

Spring 2018: Autumn 2017:
Spring 2017:
Autumn 2016:
Spring 2016:
Autumn 2015:
Spring 2015:

## Miscellaneous

A list of links to some of my personal interests: