Clockwork Cosmology
arXiv:2304.09205 · doi:10.1088/1475-7516/2023/07/062
Abstract
The higher order generalisation of the clockwork mechanism to gravitational interactions provides a means to generate an exponentially suppressed coupling to matter from a fundamental theory of multiple interacting gravitons, without introducing large hierarchies in the underlying potential and without the need for a dilaton, suggesting a possible application to the hierarchy problem. We work in the framework of ghost free multi-gravity with "nearest-neighbour" interactions, and present a formalism by which one is able to construct potentials such that the theory will always exhibit this clockwork effect. We also consider cosmological solutions to the general theory, where all metrics are of FRW form, with site-dependent scale factors/lapses. We demonstrate the existence of multiple deSitter vacua where all metrics share the same Hubble parameter, and we solve the modified Einstein equations numerically for an example clockwork model constructed using our formalism, finding that the evolution of the metric that matter couples to is essentially equivalent to that of general relativity at the modified Planck scale. It is important to stress that while we focus on the application to clockwork theories, our work is entirely general and facilitates finding cosmological solutions to any ghost free multi-gravity theory with "nearest-neighbour" interactions. Moreover, we clarify previous work on the continuum limit of the theory, which is generically a scalar-tensor braneworld, using the Randall-Sundrum model as a special case and showing how the discrete-clockwork cosmological results map to the continuum results in the appropriate limit.
arXiv comment48 pages, 4 figures
References in corpus (35)
- A Large Mass Hierarchy from a Small Extra Dimension
- An Alternative to Compactification
- The Hierarchy Problem and New Dimensions at a Millimeter
- Resummation of Massive Gravity
- Modulus Stabilization with Bulk Fields
- Generalization of the Fierz-Pauli Action
- Brane cosmological evolution in a bulk with cosmological constant
- Cosmological Relaxation of the Electroweak Scale
- Interacting Spin-2 Fields
- A Clockwork Axion
- Brane cosmology: an introduction
- Brane World Cosmology
- Realizing the relaxion from multiple axions and its UV completion with high scale supersymmetry
- Natural inflation with multiple sub-Planckian axions
- A Clockwork Theory
- Quantum Corrections in Massive Gravity
- Bimetric gravity doubly coupled to matter: theory and cosmological implications
- Phenomenology of TeV Little String Theory from Holography
- Discrete Gravitational Dimensions
- The Cosmology of Interacting Spin-2 Fields
- Disassembling the Clockwork Mechanism
- Criteria for Natural Hierarchies
- When is Multimetric Gravity Ghost-free?
- A clockwork solution to the flavor puzzle
- Quantum corrections in massive bigravity and new effective composite metrics
- A Clockwork WIMP
- The hbar Expansion in Quantum Field Theory
- Geometry and dynamics of the brane-world
- Clockwork Goldstone Bosons
- Clockwork Inflation
- Cycles of interactions in multi-gravity theories
- Generalized Clockwork Theory
- Higher Order Clockwork Gravity
- Aller guten Dinge sind drei: Cosmology with three interacting spin-2 fields
- Deconstructing higher order clockwork gravity