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Towards A Realistic Dipole Cosmology: The Dipole CDM Model
Ehsan Ebrahimian, Chethan Krishnan, Ranjini Mondol +1
Dipole cosmology is the maximally Copernican generalization of the FLRW paradigm that can incorporate bulk flows in the cosmic fluid. In this paper, we first discuss how multiple f…
A Tilt Instability in the Cosmological Principle
Chethan Krishnan, Ranjini Mondol, M. M. Sheikh-Jabbari
We show that the Friedmann-Lemaître-Robertson-Walker (FLRW) framework has an instability towards the growth of fluid flow anisotropies, even if the Universe is accelerating. This f…
Dipole Cosmology: The Copernican Paradigm Beyond FLRW
Chethan Krishnan, Ranjini Mondol, M. M. Sheikh-Jabbari
We introduce the , the idea that the Universe is a maximally Copernican cosmology, compatible with a cosmic flow. It serves as the most symmetric…
as a Universal FLRW Diagnostic
Chethan Krishnan, Ranjini Mondol
We reverse the logic behind the apparent existence of -tension, to design diagnostics for cosmological models. The basic idea is that the non-constancy of inferred from…
Hints of FLRW Breakdown from Supernovae
Chethan Krishnan, Roya Mohayaee, Eoin Ó Colgáin +2
A 10\% difference in the scale for the Hubble parameter constitutes a clear problem for cosmology. Here, considering angular distribution of Type Ia supernovae (SN) within the Pant…
Does Hubble Tension Signal a Breakdown in FLRW Cosmology?
Chethan Krishnan, Roya Mohayaee, Eoin Ó Colgáin +2
The tension between early and late Universe probes of the Hubble constant has motivated various new FLRW cosmologies. Here, we reanalyse the Hubble tension with a recent age of the…
Running Hubble Tension and a H0 Diagnostic
Chethan Krishnan, Eoin Ó Colgáin, M. M. Sheikh-Jabbari +1
Hubble tension is routinely presented as a mismatch between the Hubble constant determined locally and a value inferred from the flat CDM cosmology. In essence, the tensio…
Is there an early Universe solution to Hubble tension?
Chethan Krishnan, Eoin Ó Colgáin, Ruchika +3
We consider a low redshift cosmological dataset comprising megamasers, cosmic chronometers, type Ia SNe and BAO, which we bin according to their redshift. For each bin, w…
Dark Matter from a Dark Connection
Ranit Das, Chethan Krishnan
In the first part of this note, we observe that a non-Riemannian piece in the affine connection (a "dark connection") leads to an algebraically determined, conserved, symmetric 2-t…