Related Experiment Video
Updated: Jul 7, 2026

Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
Gravitational particle production in braneworld cosmology
1Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, I-44100, Ferrara, Italy.
Abstract:
Gravitational particle production in a time variable metric of an expanding universe is efficient only when the Hubble parameter H is not too small in comparison with the particle mass. In standard cosmology, the huge value of the Planck mass M{Pl} makes the mechanism phenomenologically irrelevant. On the other hand, in braneworld cosmology, the expansion rate of the early Universe can be much faster, and many weakly interacting particles can be abundantly created. Cosmological implications are discussed.
Related Concept Videos
The Principle of Superposition and the Gravitational Field
Newton's Law of Gravitation
Gravitation Between Spherically Symmetric Masses
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...
Detection of Black Holes
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Newton's Law of Gravitational Attraction
Newton's law of gravitational attraction is a fundamental law of physics that governs the attraction between objects. It states that the magnitude of the gravitational force between any two objects is proportional to their masses and inversely proportional...

