Geometric Foundations of Gravity 2025

Session

Monday Parallel 1 - A106

30 Jun 2025, 13:30

A106 (University of Tartu, Physicum)

67. Projective coordinate transformation in teleparallel cosmology

Manuel Hohmann (University of Tartu)

30/06/2025, 13:30

Talk

In the study of cosmology in teleparallel gravity, one can find a number of models whose dynamics turn out to have certain homogeneity properties, which allows finding a system of coordinates which separates the dynamics of "angular" and "radial" coordinates. In this split, one finds that the angular coordinates form a compact phase space, and that the qualitative dynamics in this part of the...

31. Generalized Hidden Conformal Symmetry in Quadratic f(T) Gravity

Prof. Masoud Ghezelbash

30/06/2025, 13:55

Contributed talks

Talk

We find the non-extremal charged rotating black holes in quadratic f (T ) gravity are holograph-
ically dual to two different hidden conformal field theories. The two conformal field theories can
be merged to find a very general hidden conformal field theory, which is generated by the SL(2, Z)
modular group. We also carry out the the calculation to the extremal limit of the black holes,...

56. Kerr's spacetime energy in general teleparallel theory of relativity

Roald Heinrich Ivask (University of Tartu)

30/06/2025, 14:20

Contributed talks

Talk

The work addresses the calculation of the Kerr spacetime energy within the framework of the general teleparallel equivalent of general relativity. As an alternative to general relativity, teleparallel geometry is used instead of classical Riemannian geometry, where curvature is zero while torsion and non-metricity play an important role. Unlike the Schwarzschild metric, the Kerr metric allows...

60. Warp drives in scalar-tensor theories

Joosep Lember (University of Tartu)

30/06/2025, 14:40

Contributed talks

Talk

Spacetime configurations corresponding to warp drives allow observers to traverse distances faster than the speed of light without violating the postulates of special relativity. Although appealing for space travel, it has been shown that warp drives in general relativity require exotic matter that violates energy conditions. Cosmological observations bring out the shortcomings of general...