Related Experiment Video
Updated: Sep 30, 2026

Mechanical Mapping of Spheroids Using Brillouin Spectroscopy
Published on: December 12, 2025
String inspired brane world cosmology
Cristiano Germani1, Carlos F Sopuerta
1Institute of Cosmology and Gravitation, Portsmouth University, Portsmouth PO1 2EG, United Kingdom.
Abstract:
We consider brane world scenarios including the leading correction to the Einstein-Hilbert action suggested by superstring theory, the Gauss-Bonnet term. We obtain and study the complete set of equations governing the cosmological dynamics. We find they have the same form as those in Randall-Sundrum scenarios but with time-varying four-dimensional gravitational and cosmological constants. By studying the bulk geometry we show that this variation is produced by bulk curvature terms parametrized by the mass of a black hole. Finally, we show there is a coupling between these curvature terms and matter that can be relevant for early universe cosmology.
Related Concept Videos
Couples: Scalar and Vector Formulation
A couple moment is a rotational force that tends to rotate the steering wheel. The wheel's rotation can either be in a clockwise or anticlockwise direction. The right-hand rule is a helpful method for determining the direction of a couple moment. To...
Singularity Functions for Bending Moment
Gravitation Between Spherically Symmetric Masses
Gravity between Spherical Bodies
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
Virtual Work for a System of Connected Rigid Bodies
Next,...
Schwarzschild Radius and Event Horizon
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape velocity with the...

