Theoretical systematics in testing the Cosmological Principle with the kinematic quasar dipole

Understand

The Cosmological Principle is part of the foundation that underpins the standard model of the Universe.

• In the era of precision cosmology, when stress tests of the standard model are uncovering various tensions and possible anomalies, it is critical to check the viability of this principle.
• A key test is the consistency between the kinematic dipoles of the cosmic microwave background and of the large-scale matter distribution.
• Results using radio continuum and quasar samples indicate a rough agreement in the directions of the two dipoles, but a larger than expected amplitude of the matter dipole.