Sökning: "chi-square minimization"

Hittade 2 uppsatser innehållade orden chi-square minimization.

1. 1. Galaxies as Clocks and the Universal Expansion

   Master-uppsats, KTH/Fysik

   Författare :Anders Ahlström Kjerrgren; [2021]
   Nyckelord :cosmology; cosmic chronometers; universal expansion; Hubble parameter; differential ages; galaxy age; relative age; cosmic time; chi-square minimization; monte carlo sampling; gaussian processes; kosmologi; kosmisk kronometer; universums expansion; Hubbleparametern; differentiell ålder; galaxålder; relativ ålder; kosmisk tid; chi-2-minimering; monte carlo-sampling; gaussiska processer;

   Sammanfattning : The Hubble parameter H(z) is a measure of the expansion rate of the universe at redshift z. One method to determine it relies on inferring the slope of the redshift with respect to cosmic time, where galaxy ages can be used as a proxy for the latter. This method is used by Simon et al. LÄS MER

3. 2. Advanced Characterization of Exoplanet Host Stars

   Master-uppsats, Uppsala universitet/Observationell astrofysik

   Författare :Khaled Al Moulla; [2020]
   Nyckelord :stars: exoplanet hosts - fundamental parameters - spectroscopy: HARPS - SME; stjärnor: exoplanetvärdar - fundamentala parametrar - spektroskopi: HARPS - SME;

   Sammanfattning : The spectroscopic determination of stellar properties is important for subsequent studies of exoplanet atmospheres. In this thesis, HARPS data for 6 exoplanet-hosting, late-type stars is processed to achieve an average signal-to-noise ratio of ~105. LÄS MER