Strongly Coupled Sectors in Inflation: Gapped Theories of Unparticles

Abstract

We consider a novel scenario for a strongly coupled spectator sector during inflation, that of a higher dimensional conformal field theory with large anomalous dimensions -- ``unparticles'' -- and compactify the extra dimensions. More specifically, we take generalized free fields in five dimensions, where the extra dimension is compactified to a circle. Due to the usual Kaluza-Klein mechanism, the resulting excitations carry properties of both particles and unparticles, so we dub this scenario ``gapped unparticles''. We derive a two-point function of the gapped unparticles by performing dimensional reduction. We then compute, in the collapsed limit, the four-point correlation function of conformally coupled scalars exchanging a gapped unparticle, which are used as seed functions to obtain the correlation function of primordial density perturbations. The phenomenology of the resulting correlators presents some novel features, such as oscillations with an envelope controlled by the anomalous dimension, rather than the usual value of 3/2. Depending on the value of the five-dimensional scaling dimension and effective mass of the gapped unparticles, we find a clear strategy to distinguish gapped unparticles from heavy massive scalars. If we assume the interactions are localized on a brane, gapped unparticles with different effective masses will share a universal coupling, and their exchanges produce an interesting interference pattern.

arXiv comment33 pages, 12 figures; v2: accepted version

References in corpus (50)

• A Large Mass Hierarchy from a Small Extra Dimension
• An Alternative to Compactification
• Non-Gaussian features of primordial fluctuations in single field inflationary models
• AdS/CFT Correspondence and Symmetry Breaking
• The Effective Field Theory of Inflation
• Primordial Non-Gaussianities from Inflation Models
• Open and Closed String Interpretation of SUSY CFT's on Branes with Boundaries
• Quasi-Single Field Inflation and Non-Gaussianities
• The Composite Nambu-Goldstone Higgs
• Composite Higgses
• Signatures of Supersymmetry from the Early Universe
• On Soft Limits of Inflationary Correlation Functions
• Effective field theory approach to quasi-single field inflation and effects of heavy fields
• Non-Gaussianity as a Particle Detector
• The Higgs boson from an extended symmetry
• On the one loop corrections to inflation and the CMB anisotropies
• The IR stability of de Sitter: Loop corrections to scalar propagators
• Entanglement entropy in de Sitter space
• The Cosmological Bootstrap: Weight-Shifting Operators and Scalar Seeds
• Infrared Sensitivity of Unstable Vacua
• Analyticity and Unitarity for Cosmological Correlators
• Localized Gravity in String Theory
• Productive Interactions: heavy particles and non-Gaussianity
• The Conformal Bootstrap at Finite Temperature
• Constant Curvature Black Holes
• Loop Corrections to Standard Model Fields in Inflation
• Anti-de Sitter space and black holes
• The dual of nothing
• Boostless Cosmological Collider Bootstrap
• The Scalar Chemical Potential in Cosmological Collider Physics
• Seeing Higher-Dimensional Grand Unification In Primordial Non-Gaussianities
• Bootstrapping Multi-Field Inflation: non-Gaussianities from light scalars revisited
• Phase Information in Cosmological Collider Signals
• Large-Field Inflation and the Cosmological Collider
• The IR stability of de Sitter QFT: Physical initial conditions
• Scale Dependent Local Non-Gaussianity from Loops
• On the Decay of Massive Fields in de Sitter
• Anomalous Dimensions and Non-Gaussianity
• Much Ado About Nothing
• Searching for Cosmological Collider in the Planck CMB Data
• Geometries with mismatched branes
• Continuous Spectrum on Cosmological Collider
• Composite Higgs theory
• CFTs Blueshift Tensor Fluctuations Universally
• de Sitter Space is Unstable in Quantum Gravity
• Correlation Functions of Massless Interacting Scalar Fields in de Sitter Space
• Charged Loops at the Cosmological Collider with Chemical Potential
• Bispectrum Islands
• Strongly Coupled Sectors in Inflation: Gapless Theories and Unparticles
• Perturbative unitarity bounds on field-space curvature in de Sitter spacetime: purity vs scattering amplitude

Cited by in corpus (1)

• Non-relativistic Cosmological Collider Signals