Searching for local features in primordial power spectrum using genetic algorithms

We present a no v el methodology for e xploring local features directly in the primordial power spectrum using a genetic algorithm pipeline coupled with a Boltzmann solver and Cosmic Microwave Background data (CMB). After testing the robustness of our pipeline using mock data, we apply it to the lat...

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Detalles Bibliográficos
Autores: Lodha, K., Pinol, L., Nesseris, S., Shafieloo, A., Sohn, W., Fasiello, M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/381881
Acceso en línea:http://hdl.handle.net/10261/381881
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85190864371&doi=10.1093%2fmnras%2fstae803&partnerID=40&md5=affb6ed0ea2112d086a662b55bb7dfe1
Access Level:acceso abierto
Palabra clave:Cosmic microwave background
Inflation
Methods: statistical
Descripción
Sumario:We present a no v el methodology for e xploring local features directly in the primordial power spectrum using a genetic algorithm pipeline coupled with a Boltzmann solver and Cosmic Microwave Background data (CMB). After testing the robustness of our pipeline using mock data, we apply it to the latest CMB data, including Planck 2018 and CamSpec PR4. Our model-independent approach provides an analytical reconstruction of the power spectra that best fits the data, with the unsupervised machine learning algorithm exploring a functional space built off simple 'grammar' functions. We find significant impro v ements upon the simple power -law beha viour, by Δχ2 ≲-21, consistently with more traditional model-based approaches. These best-fits al w ays address both the low-ℓ anomaly in the TT spectrum and the residual high-ℓ oscillations in the TT, TE, and EE spectra. The proposed pipeline provides an adaptable tool for exploring features in the primordial power spectrum in a model-independent way, providing valuable hints to theorists for constructing viable inflationary models that are consistent with the current and upcoming CMB surv e ys. © 2024 The Author(s).