CM4 - Tensions on LCDM cosmological model and model-independent constraints |
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Speaker |
Haridasu, Balakrishna Sandeep |
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Coauthors |
Vladimir Lukovic, Michele Moresco, Nicola Vittorio |
| Talk Title |
Model-Independent Analysis Of Low-Redshift Data: Implications For H0 And Late-Time Acceleration |
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Abstract |
In this talk, I will present an extension of the standard Gaussian Process formalism, namely the Multi-Task Gaussian Process with the ability to perform a joint learning of several cosmological data simultaneously. We have utilised the ``low-redshift'' expansion rate data from Supernovae Type-Ia (SN) Pantheon compilation, Baryon Acoustic Oscillations (BAO) and Cosmic Chronometers (CC) data in a joint analysis and tested several possible models of covariance functions to estimate the cosmological parameter. We also utilised our method to account for systematics in CC data and find an estimate of H0 = 68.52 +- 0.94 (stat) +- 2.51 (sys) km/s Mpc^-1 and a corresponding rd = 145.61 +- 2.82 (stat) +- 4.3 (sys) Mpc. Subsequently, we find constraints on the present deceleration parameter $q_0 = -0.52 \pm 0.06$ and the transition redshift zT = 0.64^{+0.12}_{-0.09}. Using the Om(z) diagnostic, we find that the concordance model is very consistent within the redshift range z<=2 and mildly discrepant for z>2. I shall also present the application of this method to reconstruct the dark energy equation of state. |
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