Quantum Chromodynamics (QCD) is the theory of the strong interactions that explains how the proton or the neutron (hadrons) are built up from elementary particles - quarks and gluons. QCD has a rich phase diagram: it exhibits among others a low-energy phase with hadronic degrees of freedom and a high-energy phase, where quarks are deconfined and the so-called quark-gluon plasma is formed. Detailed knowledge of this phase diagram help us understand the physics of various systems ranging from dense neutron stars through the early universe to heavy-ion collisions. The relevant parameters of the theory include the temperature, densities and background fields. The currently most successful approach to study the QCD phase diagram is via numerical Monte-Carlo simulation of the theory, discretized on a space-time lattice.

Within our research group, we use lattice simulations to determine the yet uncharted regions of the QCD phase diagram at nonzero (isospin) densities and background electromagnetic fields.

University of Bielefeld | March 2020 - |

Goethe-University Frankfurt | February 2016 - February 2020 |

Gergely Endrődi | - group head |

Bastian Brandt | - postdoc |

Gergely Markó | - postdoc |

Francesca Cuteri | - postdoc (2018-2019) |

Sebastian Schmalzbauer | - PhD student (2016-2020) |

Sumir Motreedja | - MSc student (2017-2018) |

Max Theilig | - MSc student (2017-2018) |

Lukas Gonglach | - MSc student (2017-2018) |

Tobias Neitzel | - MSc student (2016-2017) |

Amine Chabane | - BSc student (2019) |

The Dirac eigenvalues spread out in the complex plane as the isospin chemical potential grows. [link]. | A low-energy approximation of QCD is improved to match lattice results on inverse magnetic catalysis [link]. | ||

Charged pions decay orders of magnitude faster if exposed to strong magnetic fields [link]. | The equation of state of pion-condensed matter might allow for gravitationally bound configurations [link]. | ||

The phase diagram of isospin-dense QCD exhibits a rich structure [link]. Figure represented in PRD's Kaleidoscope. | A generative neural network learns essential features of lattice scalar field theory [link]. |

Our research is supported by the Emmy Noether Programme of the German Research Foundation under project number EN 1064/2-1.

**Gergely Endrődi**

Theoretical High Energy Group | Homepage |

Faculty of Physics, University of Bielefeld | Email: endrodi(AT)physik.uni-bielefeld.de |

Universitätsstr. 25, 33615 Bielefeld | Tel: 0521/106 - 2610 |

Office: E6-140 | Fax: 0521/106 - 2961 |