Speaker
Description
The large-scale distribution of galaxies encodes information about acoustic waves that propagated in the primordial baryon–photon plasma, leaving a characteristic feature in the two-point correlation function at scales of order 150 Mpc. By exploiting this feature, a new observable, known as the Linear Point, has been identified and shown to be a powerful cosmological standard ruler.
In this talk, I will explain that the Linear Point provides a purely geometrical way to measure cosmic distances. It enables distance measurements without the need to model the impact of non-linearities on the galaxy correlation function. This method does not assume spatial flatness or a specific model for late-time cosmic acceleration, does not require accurate knowledge of the dark-matter–tracer relation, and is independent of primordial fluctuation parameters.
I will then present ongoing work within the context of the Euclid survey, where we assess the accuracy and expected precision of Linear Point measurements. I will emphasize the importance of accounting for increasingly realistic data-related effects, one of the key challenges in modern galaxy surveys. This work is therefore crucial to employ the Linear Point standard ruler as a robust and fully geometric probe for characterizing the late-time expansion history of the Universe.
| Other topic / keywords: | Baryon acoustic oscillations, Euclid Survey, dark energy, cosmological parameters, spectroscopic survey |
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