{"knowledge_schema": {"broad_category": "Astronomy \u2192 Cosmology \u2192 Distance Measurement", "refinement": "This problem involves understanding the relationship between redshift, wavelength, and comoving distance in the context of the Lambda-CDM cosmological model.", "specific_scope": "The focus is on determining the comoving distance of a quasar based on its observed peak wavelength and the parameters of the universe, specifically using the Hubble constant and density parameters.", "goal": "Calculate the comoving distance to the quasar based on its observed properties and the cosmological model."}, "summary": "This problem relates to cosmology, specifically the measurement of distances in the universe using the Lambda-CDM model. The observed peak wavelength of the quasar at 790 nm suggests a redshift that can be used to infer its comoving distance from Earth. Given the parameters of the universe, including the Hubble constant and density parameters, the task is to determine the quasar's distance, with the answer being 8 Gpc. This highlights the importance of understanding how light from distant objects is affected by the expansion of the universe."}