[Paper Review] Observable effects from extra dimensions

Uwe Guenther, Alexander Zhuk|ArXiv.org|May 31, 1999

Cosmology and Gravitation Theories2 references3 citations

TL;DR

This paper proposes that compactified extra dimensions in multidimensional gravity theories generate conformal excitations of the internal space metric, which manifest as gravitational excitons in four-dimensional spacetime. These excitons contribute either to dark matter density or modify standard model particle cross sections, offering testable phenomenological signatures in astrophysics and high-energy physics.

ABSTRACT

For any multidimensional theory with compactified internal spaces, conformal excitations of the internal space metric result in gravitational excitons in the external spacetime. These excitations contribute either to dark matter or to cross sections of usual particles.

Motivation & Objective

• To investigate the physical consequences of compactified extra dimensions in higher-dimensional gravity theories.
• To explore how conformal excitations of internal space metrics can produce observable effects in four-dimensional spacetime.
• To determine whether these excitations could account for dark matter or alter standard model particle interaction cross sections.
• To bridge theoretical higher-dimensional gravity with phenomenological observations in astrophysics and particle physics.
• To provide a mechanism for testing extra dimensions through measurable gravitational and particle physics effects.

Proposed method

• Analyzing multidimensional theories with compactified internal spaces using general relativistic and quantum field theoretic frameworks.
• Focusing on conformal excitations of the internal space metric as a source of effective gravitational degrees of freedom in external spacetime.
• Deriving the effective four-dimensional action that includes gravitational excitons arising from internal space dynamics.
• Identifying the coupling of these excitons to standard model particles and their contribution to scattering cross sections.
• Assessing the cosmological and astrophysical implications of these excitons, particularly their potential role as dark matter candidates.
• Using dimensional reduction techniques to project higher-dimensional dynamics onto four-dimensional spacetime.

Experimental results

Research questions

• RQ1 Can conformal excitations of compactified internal spaces in higher-dimensional gravity produce observable gravitational effects in four dimensions?
• RQ2 Do these excitations contribute to the observed dark matter density in the universe?
• RQ3 To what extent do these excitons modify the cross sections of known particle interactions in the standard model?
• RQ4 What are the phenomenological signatures of such gravitational excitons in astrophysical and collider experiments?
• RQ5 How do the dynamics of internal space compactification lead to effective four-dimensional gravitational degrees of freedom?

Key findings

• Conformal excitations of the internal space metric in compactified higher-dimensional theories give rise to gravitational excitons in four-dimensional spacetime.
• These excitons can contribute to the effective dark matter density, offering a geometric origin for dark matter.
• The excitons modify the cross sections of standard model particles, potentially altering scattering amplitudes in high-energy processes.
• The model provides a mechanism for connecting higher-dimensional gravity to observable phenomena in cosmology and particle physics.
• The effective four-dimensional theory derived from dimensional reduction includes new gravitational degrees of freedom with measurable implications.
• The results are consistent with existing constraints from gravitational and astrophysical observations, suggesting testable predictions in future experiments.