BEGIN:VCALENDAR VERSION:2.0 PRODID:-//wp-events-plugin.com//6.4.7.2//EN TZID:Europe/Paris X-WR-TIMEZONE:Europe/Paris BEGIN:VEVENT UID:0-1049@lptms.universite-paris-saclay.fr DTSTART;TZID=Europe/Paris:20250916T110000 DTEND;TZID=Europe/Paris:20250916T120000 DTSTAMP:20250911T140618Z URL:http://www.lptms.universite-paris-saclay.fr/seminars/seminaire-du-lptm s-kim-kreienkamp-tu-berlin/ SUMMARY:Séminaire du LPTMS : Kim Kreienkamp (TU Berlin) - Salle des sémin aires du FAST et du LPTMS\, bâtiment Pascal n°530 - 16 Sep 25 11:00 DESCRIPTION:Symmetry breaking in active non-reciprocal systems\n \;\nKi m Kreienkamp (TU Berlin)\n \;\n\nNon-reciprocal couplings significantl y impact the dynamical behavior in mixtures. A particularly striking conse quence of such couplings is the spontaneous emergence of time-dependent ph ases that break parity-time symmetry. Here\, we study a paradigmatic model of a non-reciprocal polar active mixture with completely symmetric repuls ion. Using a combination of field theory and particle-based simulations\, we identify two qualitatively distinct regimes of non-reciprocity-induced dynamics. In the regime of weak intra-species alignment\, non-reciprocity leads to asymmetric clustering in which predominantly one of the two speci es forms clusters. Notably\, the asymmetric density dynamics is driven alo ne by non-reciprocal orientational couplings. In contrast\, in the strongl y coupled regime\, the corresponding field\ntheory exhibits exceptional po ints that have been associated with the emergence of chiral phases where t he polarization direction rotates over time. Our simulations confirm that spontaneous chirality arises at the particle level. In particular\, we obs erve chimera-like states with coexisting locally synchronized and disorder ed regions. Both the spontaneous chirality and entropy production rate pea k at coupling\nstrengths associated with exceptional points. Our results h ighlight the diverse effects of non-reciprocity across different scales. CATEGORIES:seminars LOCATION:Salle des séminaires du FAST et du LPTMS\, bâtiment Pascal n°53 0\, rue André Riviere\, Orsay\, 91405\, France X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=rue André Riviere\, Orsay\ , 91405\, France;X-APPLE-RADIUS=100;X-TITLE=Salle des séminaires du FAST et du LPTMS\, bâtiment Pascal n°530:geo:0,0 END:VEVENT BEGIN:VTIMEZONE TZID:Europe/Paris X-LIC-LOCATION:Europe/Paris BEGIN:DAYLIGHT DTSTART:20250330T030000 TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST END:DAYLIGHT END:VTIMEZONE END:VCALENDAR