Room 208, School of Arts and Sciences
Central Campus
CDM isocurvature power with large blue spectral index can explain the 2-sigma hint in Planck data and recent JWST observation of high redshift galaxies. A well-known method for generating a large blue spectral index for axionic isocurvature perturbations involves a flat direction without a quartic potential term for the axion field’s radial partner. In this talk, we discuss how a large blue spectral index can be achieved even with a quartic potential term linked to the Peccei-Quinn symmetry breaking radial partner. We utilize the fact that a large radial direction with a quartic term can naturally induce a “conformal limit”, producing an isocurvature spectral index of 3. Alternatively, this limit can be seen as the angular momentum of the initial conditions slowing the radial field or as a superfluid limit. The large angular momentum necessitates a careful quantisation process to establish the vacuum state. We outline the parametric region that aligns with axion dark matter and isocurvature cosmology, and discuss prospects for future detection.
Dr Tadepalli Chaitanya earned his MS and PhD in Physics under the supervision of Professor Daniel Chung at the University of Wisconsin-Madison. He recently joined Indiana University as a postdoctoral fellow, collaborating with Assistant Professor Raymond Co.
