Lawrence Krauss on Cosmic Strings

by Paul Gilster on December 31, 2005

Centauri Dreams recently examined wormholes and their possible survival from the early universe through the mechanism of a negative mass cosmic string. But what exactly is a cosmic string? Here’s Lawrence Krauss on the subject:

“During a phase transition in materials — as when water boils, say, or freezes, the configuration of the material’s constituent particles changes. When water freezes, it forms a crystalline structure. As crystals aligned in various distances grow, they can meet to form random lines, which create the patterns that looks so pretty on a window in the winter. During a phase transition in the early universe, the configuration of matter, radiation, and empty space (which, I remind you, can carry energy) changes, too. Sometimes during these transitions, various regions of the universe relax into different configurations. As these configurations grow, they too can eventually meet — sometimes at a point, and sometimes along a line, marking a boundary between the regions. Energy becomes trapped in this boundary line, and it forms what we call a cosmic string.

“We have no idea whether cosmic strings actually were created in the early universe, but if they were and lasted up to the present time they could produce some fascinating effects. They would be infinitesimally thin — thinner than a proton — yet the mass density they carry would be enormous, up to a million million tons per centimeter. They might form the seeds around which matter collapses to form galaxies, for example. They would also ‘vibrate,’ producing not subspace harmonics but gravitational waves. Indeed, we may well detect the gravitational wave signature of a cosmic string before we ever directly observe the string itself.”

From The Physics of Star Trek (New York: HarperCollins, 1995), pp. 149-150.

Of course, what Landis, Forward and the other authors of the paper “Natural Wormholes as Gravitational Lenses” were talking about was not just a cosmic string, but one possessing negative mass, and it would have to wrap itself around a wormhole in order to stabilize it so it could survive to the present time. Do such structures exist? If so, it is possible that advances in both space-based and ground astronomy will eventually prove the point, but even then, we’ll be left to speculate about where or when such a wormhole might lead.

{ 2 comments }

Timothy J Mayes March 8, 2007 at 15:38

a gravitational propulsion device would probably have to be based on a successful , and proven theory of quantum gravity in the future.
If qauntum gravity exist then it would be possible to convert one of the
other three fundamental forces into gravitation, and generate gravitational
waves in space time.This sort of discovery could enable some form of warp drive or hyper drive if it happened.
tim

ljk August 10, 2009 at 0:48

The Search for a Realistic String Model at LHC

Authors: James A. Maxin, Van E. Mayes, D.V. Nanopoulos

(Submitted on 6 Aug 2009)

Abstract: We survey the low-energy supersymmetry phenomenology of a three-family Pati-Salam model constructed from intersecting D6-branes in Type IIA string theory on the T^6/(Z_2 x Z_2) orientifold which possesses many of the phenomenological properties desired in string model-building.

In the model, there is no exotic matter in the low-energy spectrum, the correct mass hierarchies for quarks and leptons may be obtained, and the gauge couplings are automatically unified at the string scale. We calculate the supersymmetry breaking soft terms and the corresponding low-energy supersymmetry particle spectra for the model.

We find the WMAP constrained dark matter density can be generated in this model in the stau-neutralino and chargino-neutralino coannihilation regions, with expected final states at LHC consisting of low energy leptons and O(GeV) neutrinos.

Moreover, we expect final states in the supercritical string cosmology (SSC) scenario to comprise high energy leptons and O(GeV) neutrinos. We discuss the method for the determination of the model parameters from the final states.

Comments: 35 pages, 4 figures

Subjects: High Energy Physics – Phenomenology (hep-ph); Cosmology and
Extragalactic Astrophysics (astro-ph.CO); High Energy Physics – Experiment (hep-ex); High Energy Physics – Theory (hep-th)

Cite as: arXiv:0908.0915v1 [hep-ph]

Submission history

From: James Maxin [view email]

[v1] Thu, 6 Aug 2009 17:21:49 GMT (432kb)

http://arxiv.org/abs/0908.0915

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