Publications Research Note Published Physics Research Note Pre-Registration Note observational-pre-registration Balkenhol et al., end-of-2025 CMB and BAO constraints on inflationary observables. true 2026-04-25T00:00:00+00:00 research-notes, physics, cosmology, pre-registration inflation, cmb, bao, no inflaton inflation, tensor-to-scalar ratio, scalar spectral index, no inflaton A pre-registration note placing the categorical inflationary pair against late-2025 CMB and BAO constraints.
Research Note ·

Inflationary Observables Without an Inflaton

A categorical pre-registration versus end-of-2025 CMB and BAO constraints

A pre-registration note placing the categorical inflationary pair against late-2025 CMB and BAO constraints.

RN003 Pre-Registration Note Physics Published PDF available

Publication Metadata

Publication IDRN003
Note typePre-Registration Note
Subtypeobservational pre registration
DomainPhysics
Date25 April 2026

Anchor paper: Balkenhol et al., end-of-2025 CMB and BAO constraints on inflationary observables.

Review status: Program pre-registration; external review not yet completed.

Abstract

The note compares the Panta Rhei no-inflaton pre-registration for the tensor-to-scalar ratio and scalar spectral index with late-2025 CMB and BAO constraints. It separates the framework's internal commitment from external acceptance and identifies near-term falsification routes.

Anchor Paper and Context

End-of-2025 CMB and BAO inflation constraints

The anchor result summarizes the observational state of the scalar spectral index and tensor-to-scalar ratio within standard inflationary model families.

Relation to this note: Used as the empirical comparison plane for a categorical no-inflaton pre-registration.

Claim Boundary

Core Claim

The framework pre-registers inflationary observables from the fibered-product structure rather than from a scalar inflaton potential.

What This Note Does Not Claim

  • It does not claim that standard inflationary model classes are mathematically inconsistent.
  • It does not claim that CMB and BAO data have externally accepted the categorical interpretation.
  • It does not bypass future CMB B-mode falsification.

Falsification and Challenge Surface

  • A confirmed tensor-to-scalar ratio outside the stated categorical window.
  • A scalar spectral index measurement incompatible with the structural e-fold count.
  • Failure of the no-inflaton derivation chain or measurement bridge.

Verification Surface

Statuspending physics verification
Modeobservational pre registration

Reading Note

The PDF contains the full argument. This web page records the public metadata, claim boundary, verification posture, and related site surfaces for the citable Research Note artifact.

Citation

Fuchs, Thorsten, and Anna-Sophie Fuchs. "Inflationary Observables Without an Inflaton." Panta Rhei Research Notes, 25 April 2026. PDF.

PDF artifact

Use the PDF as the citable pre-registration artifact.

Program pre-registration; external review not yet completed.

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