The Duality Redshift: How Photons Morph into Dark Matter and Resolve the Hubble Tension ✦
An operational model of redshift duality is tested, where the observed shift includes a standard metric component and an additional quantum contribution from photon energy conversion to effective mass, dependent on path and frequency. Analysis of the Pantheon+SH0ES data compilation shows that the metric Hubble constant H_Λ recovers to a value consistent with the baseline Planck result (67.4 km/s/Mpc) within ≲0.33σ. Redshift binning demonstrates that in standard flat ΛCDM, an apparent Hubble parameter drift emerges, while the hybrid model restores its constancy. Recalculated cosmological quantities point to the possibility of smoothing out anomalies associated with galaxies at large redshifts. The results suggest that further study of redshift duality in observational cosmology is warranted, while maintaining consistency with flat ΛCDM anchored on Planck.
Context
The discrepancy between the Hubble constant measured from cosmic microwave background fluctuations (67.4 km/s/Mpc) and from Cepheid-calibrated Type Ia supernovae (73.0 km/s/Mpc) has reached 5σ. This Hubble tension challenges the standard ΛCDM cosmology and calls for either a revision of observational systematics or the introduction of new physics, such as evolving dark energy. However, dynamical dark energy models do not provide a unified answer and struggle to fit all data. Our work suggests a radically different path: preserving the ΛCDM framework while adding a new, non-metric redshift channel arising from photon-vacuum interactions.
Methods
We used the publicly available Pantheon+SH0ES dataset, comprising 1701 standardized Type Ia supernovae. In addition to the standard cosmological redshift z_Λ due to the expansion of the Universe, we introduced a frequency-(wavelength)-dependent component z_q that accumulates along the line of sight as exp(PX), where P is the photon-to-nonradiative energy conversion coefficient (WMC). We parameterized P as an effective attenuation constant per unit length, analogous to the Beer–Lambert law. Photon number conservation in the beam was assumed, and the WMC frequency dependence was chosen to mimic interstellar reddening (with a coefficient β≈3) while being negligible in the microwave range, preserving the CMB blackbody spectrum. Regression analysis was performed via MCMC using both diagonal and full covariance matrices (including systematics). A key assumption was 'dust-mimicking magnitude compensation' (DMC): the standard supernova color correction inadvertently restores the true luminosity by compensating for WMC dimming, but leaves an excess redshift in the spectral lines.
Results
The global fit of the hybrid model (with flat ΛCDM parameters fixed to the Planck values: Ω_m=0.315, H_0=67.4 km/s/Mpc) yielded a WMC conversion rate H_q = 4.9 ± 0.15 km/s/Mpc (in the diagonal mode). The metric Hubble constant H_Λ remains at 67.4 km/s/Mpc, and the near-zero distance modulus offset M~0 confirms the recovery of true luminosity. A crucial result comes from tomographic analysis: when dividing the sample into redshift bins in standard ΛCDM, a statistically significant positive drift of H_Λ(z) emerges with a slope of ~3.2 km/s/Mpc per unit z, equivalent to a 'phantom crossing' in dynamical dark energy models. In the hybrid model, this drift vanishes (slope ~0.0), and H_Λ in each bin remains compatible with the Planck value within ≲0.33σ. BIC comparison shows that the hybrid model with one extra parameter (H_q) is often preferred not only over fixed ΛCDM but also over extensions with variable dark energy. Additionally, diagnostic indices—luminosity distance ratio, angular diameter distance, time delay, and age—demonstrate that without accounting for WMC, high-z galaxies appear systematically more massive, more compact, and prematurely evolved.
Implications
The results indicate that the Hubble tension may not stem from distance measurement errors or new dark energy, but from a fundamental process: as electromagnetic radiation travels, part of its energy leaks into 'hidden' degrees of freedom that behave as effective mass (a dark matter analogue). This conversion, formally similar to pair production in strong fields (Schwinger mechanism) but operating on cosmological scales, naturally explains the observed discrepancy without altering the Universe's geometry. Moreover, the proposed mechanism offers a new perspective on the origin of dark matter as a slowly accumulated outcome of light interacting with the vacuum.
Future development
To test the WMC hypothesis, laboratory optical experiments are needed. Modern optical atomic clocks achieve 10⁻¹⁸ precision, potentially allowing measurement of the predicted frequency shift of order 10⁻¹⁵ over distances comparable to Pluto's orbit (~40 AU) via Deep Space Optical Communications. Multi-frequency heterodyne interferometry would separate the chromatic WMC signal from achromatic Doppler and gravitational shifts. Additionally, a reanalysis of weak gravitational lensing data is required to remove systematic distance-scale distortions in the local Universe (z≲1.7), which could resolve the S8 tension. Finally, if WMC indeed generates dark matter, it would reshape our understanding of structure formation.
Impact
The proposed hypothesis could affect nearly all areas of observational cosmology, from spectroscopy of distant galaxies to the interpretation of JWST and gravitational lensing data. A recalibration of the distance and mass scales for high-redshift objects will be particularly important.
Next steps
Immediate steps include: a full reprocessing of supernova luminosity calibrations with explicit frequency-dependent WMC, testing the model on other tracers (Mira variables, surface brightness fluctuations), and direct detection of the WMC signal in space-based laser experiments.
Key open problems
The WMC model is directly connected to unsolved problems in physics: the nature of dark matter, dark energy, and the quantum structure of the vacuum. If light truly converts into massive particles, it would require a revision of gravitational dynamics in the early Universe and could explain why we don't observe photon decay in the lab—the effect becomes noticeable only on cosmological scales due to cumulative action. This also raises questions about dissipative properties of spacetime itself.
🎯 In classical electrodynamics, wave propagation in an absorbing medium is described by the imaginary part of the refractive index. Applying this analogy to the vacuum, the predicted WMC attenuation rate corresponds to an effective viscosity of the Universe of only ~1.6×10⁻¹⁹ s⁻¹, making it the most dilute and nearly ideal 'fluid'.
Key numbers
- Hubble constant from Planck: 67.4 km/s/Mpc
- Hubble constant from SH0ES supernovae: 73.0 km/s/Mpc
- Recovered metric Hubble constant: 67.4 km/s/Mpc
- WMC attenuation parameter H_q: ≈5 km/s/Mpc
- Distance modulus offset Δμ: ~0.17 mag