Compare · Before the Universe

Conformal Cyclic Cosmology (CCC) vs Pre-Big Bang (Gasperini-Veneziano)

← Back to Conformal Cyclic Cosmology (CCC)

Cyclic & Bouncing Cosmologies· within family

	Conformal Cyclic Cosmology (CCC) Speculative	Pre-Big Bang (Gasperini-Veneziano) Speculative
Proposed	2005	1993
Key figures	Roger Penrose	Maurizio Gasperini, Gabriele Veneziano
In one sentence	A previous "aeon" existed. Its conformally smooth heat-death geometry became our Big Bang.	In string cosmology, a weakly-coupled contracting phase preceded the Big Bang, driven by the dilaton field.
Predictions	Concentric CMB rings (Hawking points) Smooth conformal transition, no [[singularity]] Massless [[dark matter]] required at aeon boundary	Specific tilted spectrum of gravitational waves (blue tilt) Before the Bang, a quiet low-energy state described by string theory, where all the forces were very weak (a weakly-coupled string vacuum) Universe is asymmetric across the Bang
Where it breaks	Independent analyses find rings consistent with noise Requires massless dark matter, not established Community consensus is largely skeptical Bodnia et al. (2024) find no statistically significant low-variance circles or Hawking points in Planck/WMAP data using a ResNet18 ML pipeline, contradicting earlier Gurzadyan-Penrose claims.	Pre-Bang gravity-wave spectrum not yet detected Mechanism of the bounce remains incompletely understood Less developed than LQC bounce
Key unresolved problem	The missing fingerprint: other teams cannot find the predicted Hawking-point rings, faint circles in the cosmic microwave background, leaving CCC's one big observational claim statistically unsupported.	The breakdown at the bounce: at the moment of greatest curvature the low-energy string equations stop working, and no one has an accepted replacement, so the switch from shrinking to expanding is not fully described.
Reader vote	No votes yet	No votes yet

Conformal Cyclic Cosmology (CCC)

2005 · Speculative

Pre-Big Bang (Gasperini-Veneziano)

1993 · Speculative

Proposed

2005

1993

Key figures

Roger Penrose

Maurizio Gasperini, Gabriele Veneziano

In one sentence

A previous "aeon" existed. Its conformally smooth heat-death geometry became our Big Bang.

In string cosmology, a weakly-coupled contracting phase preceded the Big Bang, driven by the dilaton field.

Predictions

Concentric CMB rings (Hawking points)
Smooth conformal transition, no [[singularity]]
Massless [[dark matter]] required at aeon boundary

Specific tilted spectrum of gravitational waves (blue tilt)
Before the Bang, a quiet low-energy state described by string theory, where all the forces were very weak (a weakly-coupled string vacuum)
Universe is asymmetric across the Bang

Where it breaks

Independent analyses find rings consistent with noise
Requires massless dark matter, not established
Community consensus is largely skeptical
Bodnia et al. (2024) find no statistically significant low-variance circles or Hawking points in Planck/WMAP data using a ResNet18 ML pipeline, contradicting earlier Gurzadyan-Penrose claims.

Pre-Bang gravity-wave spectrum not yet detected
Mechanism of the bounce remains incompletely understood
Less developed than LQC bounce

Key unresolved problem

The missing fingerprint: other teams cannot find the predicted Hawking-point rings, faint circles in the cosmic microwave background, leaving CCC's one big observational claim statistically unsupported.

The breakdown at the bounce: at the moment of greatest curvature the low-energy string equations stop working, and no one has an accepted replacement, so the switch from shrinking to expanding is not fully described.

Reader vote

No votes yet