BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Christos Charmoussis (University of Paris-Saclay) DTSTART:20260204T100000Z DTEND:20260204T110000Z DTSTAMP:20260422T212108Z UID:MathematicalPhysicsSeminarAuth/1 DESCRIPTION:Title: Black Holes with Primary Hair\nby Christos Char moussis (University of Paris-Saclay) as part of AUTH-MATH-PH\n\nLecture he ld in Room M2 in the Department of Mathematics\, Aristotle University of T hessaloniki.\n\nAbstract\nGeneral Relativity black holes are described by mass\, angular momentum and electric/magnetic charge. They are said to hav e no hair in the\nsense that they are uniquely defined by these charges as measured from a far away observer and not by other details. These charact eristics are\nthought to persist in modified theories of gravity by so cal led no hair theorems. We will see how one can bifurcate the no hair paradi gm and\nconstruct explicit black hole solutions that admit additional inde pendent charges in theories modifying general relativity. These black hole s have\nadditional properties that make them quite different from their GR solutions. We will give two different theories with two different explici t examples\nand their properties.\n\nFor the online Meeting ID and Passcod e:\nMeeting ID: 914 5708 9061\nPasscode: 928529\n LOCATION:https://researchseminars.org/talk/MathematicalPhysicsSeminarAuth/ 1/ END:VEVENT BEGIN:VEVENT SUMMARY:Nikolaos Athanasiou (Aristotle University of Thessaloniki) DTSTART:20260304T130000Z DTEND:20260304T140000Z DTSTAMP:20260422T212108Z UID:MathematicalPhysicsSeminarAuth/2 DESCRIPTION:Title: The Einstein-Vlasov System in a Large Data Regime\nby Nikolaos Athanasiou (Aristotle University of Thessaloniki) as part of AUTH-MATH-PH\n\nLecture held in Room M2 in the Department of Mathematic s\, Aristotle University of Thessaloniki.\n\nAbstract\nIn this talk\, our object of study is the Einstein-Vlasov system with a massless Vlasov matte r field. Our main contribution is the provision of a novel technique for c ontrolling the Vlasov matter in a double null gauge\, relying purely on ve ctor field commutation and bypassing the need for introducing Jacobi field s\, which has so far been the only existing technique outside of symmetry in this gauge. To obtain it\, we have to overcome stringent regularity iss ues that are existent along this path. Because it relies solely on vector field commutation\, our technique is fundamentally simple and flexible eno ugh to be applicable in any data regime. We thus anticipate this to be a h elpful tool for many subsequent problems regarding the Einstein-Vlasov sys tem\, including\, for instance\, simplified approaches to the proof of non linear stability of Minkowski spacetime with massless Vlasov matter\, scat tering problems for data close to black holes\, approaching cosmic censors hip\, etc. We further introduce and work in an optimal regularity framewor k\, using this new technique\, to obtain a large data semi-global existenc e theorem and a dynamical trapped surface formation statement for our syst em. Joint work with Puskar Mondal and Shing-Tung Yau.\n\nMeeting ID: 914 5 708 9061\nPasscode: 928529\n LOCATION:https://researchseminars.org/talk/MathematicalPhysicsSeminarAuth/ 2/ END:VEVENT BEGIN:VEVENT SUMMARY:Grigorios Fournodavlos (University of Crete-FORTH) DTSTART:20260402T100000Z DTEND:20260402T110000Z DTSTAMP:20260422T212108Z UID:MathematicalPhysicsSeminarAuth/3 DESCRIPTION:Title: Big Bang Singularities\nby Grigorios Fournodavl os (University of Crete-FORTH) as part of AUTH-MATH-PH\n\nLecture held in Room M2 in the Department of Mathematics\, Aristotle University of Thessal oniki.\n\nAbstract\nWe will present the classical cosmological models in g eneral relativity that contain a Big Bang singularity and discuss their dy namics. The conjectural picture in physics was put forth in the late 60's - early 70's. Despite numerous efforts\, it has only been partially confir med. We will review recent state of the art mathematical results and pose questions for future work.\n\nFor the online Meeting ID and Passcode: Meet ing ID: 914 5708 9061 Passcode: 928529\n LOCATION:https://researchseminars.org/talk/MathematicalPhysicsSeminarAuth/ 3/ END:VEVENT END:VCALENDAR