HAL CCSD
Optimal estimator for resonance bispectra in the CMB
Münchmeyer, Moritz
Meerburg, P. Daniel
Wandelt, Benjamin D.
Institut d'Astrophysique de Paris (IAP) ; Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Université Paris Cité (UPCité)
International audience
Physical Review D
insu-03644760
https://insu.hal.science/insu-03644760
https://insu.hal.science/insu-03644760/document
https://insu.hal.science/insu-03644760/file/PhysRevD.91.043534.pdf
https://insu.hal.science/insu-03644760
Physical Review D, 2015, 91, ⟨10.1103/PhysRevD.91.043534⟩
ARXIV: 1412.3461
info:eu-repo/semantics/altIdentifier/arxiv/1412.3461
BIBCODE: 2015PhRvD..91d3534M
DOI: 10.1103/PhysRevD.91.043534
info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevD.91.043534
en
98.80.-k
98.80.Cq
98.80.Es
Cosmology
Particle-theory and field-theory models of the early Universe
Observational cosmology
Astrophysics - Cosmology and Nongalactic Astrophysics
[SDU]Sciences of the Universe [physics]
info:eu-repo/semantics/article
Journal articles
We propose an (optimal) estimator for a CMB bispectrum containing logarithmically spaced oscillations. There is tremendous theoretical interest in such bispectra, and they are predicted by a plethora of models, including axion monodromy models of inflation and initial state modifications. The number of resolved logarithmical oscillations in the bispectrum is limited due to the discrete resolution of the multipole bispectrum. We derive a simple relation between the maximum number of resolved oscillations and the frequency. We investigate several ways to factorize the primordial bispectrum, and conclude that a one-dimensional expansion in the sum of the momenta ∑k<SUB>i</SUB>=k<SUB>t</SUB> is the most efficient and flexible approach. We compare the expansion to the exact result in multipole space and show for ω<SUB>eff</SUB>=100 that O (1 0<SUP>3</SUP>) modes are sufficient for an accurate reconstruction. We compute the expected σ<SUB>f<SUB>NL</SUB></SUB> and find that within an effective field theory (EFT) the overall signal to noise scales as S /N ∝ω<SUP>3 /2</SUP>. Using only the temperature data we find S /N ∼O (1 - 1 0<SUP>2</SUP>) for the frequency domain set by the EFT.
2015
info:eu-repo/semantics/OpenAccess