20–22 Jan 2026
Faculty of Science, Cairo University, Egypt
Africa/Cairo timezone

Exact solutions of Finslerian versions of Einstein's field equations

21 Jan 2026, 09:30
35m
Ibn Sina Hall (Faculty of Science, Cairo University, Egypt)

Ibn Sina Hall

Faculty of Science, Cairo University, Egypt

Speaker

Ebtsam H. Taha (Department of Mathematics, Faculty of science, Cairo University)

Description

Finsler gravity is a modern extension of Einstein's General Relativity, using Finsler geometry (which generalizes Riemannian geometry) to describe spacetime, allowing for direction-dependent physics, potentially explaining phenomena like dark energy or dark matter, and offering new perspectives on cosmology by studying non-Riemannian "Finsler spacetimes" that still recover Einstein's theory in specific limits, exploring modified gravity theories. Special famous Finsler metrics are $(\alpha, \beta)$-metrics. Certain $(\alpha, \beta)$-metrics that appear naturally as a spacetime geometry that is compatible with Lorentz symmetry breaking. These metrics, such as generalized m-Kropina metrics (see, [3]), have the potential to be useful in modified gravity and cosmology. As part of my research, I investigate the geometric properties of the generalized m-Kropina metrics, such as the conditions under which they become Einstein-type metrics. As a result, we are able to determine the circumstances under which a generalized $m$-Kropina metric $F$ becomes an exact solution to either "Chen and Shen's Finslerian non-vacuum field equation" or "Pfeifer and Wohlfarth's vacuum field equation" (see, [1], [2]). Examples of generalized $m$-Kropina metrics in dimension $4$ are presented here. These metrics have significant applications in modified gravity and cosmology. The main results of this talk is contained in [4].

[1] B. Chen and Y. B. Shen, On a class of critical Riemann-Finsler metrics, Publ. Math. Debrecen
72/3-4 (2008) 451-468.
[2] C. Pfeifer and M. N. R. Wohlfarth, Finsler geometric extension of Einstein gravity, Phys. Rev. D 85, 064009, 2012.
[3] C. Pfeifer, S. Heefer and A. Fuster, Identifying Berwald Finsler Geometries, Differential Geom. Appl. 79, 101817 (2021).
[4] Ebtsam H. Taha, "On the generalized m-Kropina metrics", arXiv:2510.22466 [math.DG].

Author

Ebtsam H. Taha (Department of Mathematics, Faculty of science, Cairo University)

Presentation materials