Seminars take place virtually on a biweekly basis on Thursdays at 16:00.
In order to be added to the mailing list, please email shaharhadar@sci.haifa.ac.il.
Fall semester 2026/27
15/10: Luis Lehner (Perimeter)
Title: Gravity through a non-linear lens: turbulence, and energy cascades
Abstract: The dynamics of gravity has mostly been understood through the lens of perturbations: a background, a spectrum of modes, and corrections to it. Taking instead a nonlinear point of view, in which many modes interact and energy moves across scales, can both illuminate familiar phenomena and point to new directions. Recent black-hole simulations provide the motivation, showing spectral transfer with the character of fluid turbulence. I will discuss what structures in Einstein’s equations could organize such behavior, drawing on ideas from two-dimensional turbulence, and where this view leads: for the late-time dynamics of black holes, for what is radiated to infinity, and for questions that the perturbative picture does not naturally raise.
29/10: Elena Emtsova (Ariel & Bar Ilan)
Title: Noether Conserved Quantities in Teleparallel Equivalents of General Relativity
Abstract: Teleparallel equivalents of general relativity describe gravity in terms of torsion (TEGR) or nonmetricity (STEGR), rather than curvature. In this talk, I will review the construction of covariant Noether currents, superpotentials, and conserved charges in both formulations. Particular attention will be paid to the role of teleparallel connections, gauge choices, and observers in defining gravitational energy and momentum. I will illustrate the formalism through applications to Schwarzschild and Kerr black holes, cosmological solutions, and gravitational waves, discussing the physical interpretation of conserved quantities and their relation to the equivalence principle.
12/11: Harvey Reall (Cambridge)
Title: TBA
Abstract: TBA
Spring semester 2026/27