The universe is less uniform than we thought – cosmology may need a radical rethink

2 responses

1. 

   toandfromdavid

   July 6, 2026

   Dear Professor Sylos Labini and Dr Galoppo,

   I recently read with great interest your Nature paper, together with the accompanying reports in Science and Scientific American, discussing your analysis of the DESI data and the possibility that the universe remains structured on much larger scales than predicted by the standard cosmological model.

   Whether or not your conclusions withstand further scrutiny, I believe the work is important because it challenges one of the key assumptions underlying ΛCDM—that the universe becomes statistically homogeneous on sufficiently large scales. It is encouraging to see fundamental assumptions being tested rather than simply accepted.

   For the past several years, I have been developing an alternative cosmological framework, The Infinite Recycling Multiverse (IRM): Eternal Dynamic Equilibrium, which has recently been published as a book. Although my model differs substantially from yours, it likewise begins by questioning several assumptions of the standard model.

   The central idea is straightforward.

   If spacetime is infinite and governed everywhere by the same physical laws, then Big-Bang-like expansions need not be unique events but may occur throughout an infinite spacetime background. Our observable universe would therefore be one finite expanding bubble universe embedded within an infinite spacetime background rather than the entirety of existence.

   As bubble universes evolve, gravitational collapse ultimately produces populations of black holes. Over immense timescales, black holes originating from neighbouring bubble universes can interact and merge within the shared infinite spacetime background, eventually forming extremely massive progenitor objects. When such a progenitor becomes unstable, it gives rise to a new expanding bubble universe, providing a continuous recycling process without requiring creation from nothing.

   Within this framework, I argue that several longstanding cosmological problems—including the horizon problem, flatness problem, singularities, dark energy, and the long-term fate of the universe—may be viewed as consequences of this larger picture rather than requiring separate mechanisms.

   One aspect that may be relevant to your work is that IRM does not assume a bubble universe is globally homogeneous. Instead, our observable universe represents only a small region within a much larger finite bubble universe embedded within an infinite spacetime background. If the bubble possesses a radial density and expansion profile inherited from its formation, then observations extending over sufficiently large scales may eventually reveal departures from perfect homogeneity and isotropy. In principle, one might expect systematic differences with direction and distance, reflecting our position within the larger bubble—for example, a gradual trend toward higher average density in the direction of the bubble’s centre and lower average density in the opposite direction.

   If you have time, I would be grateful for any comments on whether you consider the overall framework physically plausible, regardless of whether you agree with its specific conclusions. I appreciate that you are both extremely busy, so I have also attached a condensed summary in case it is more convenient than reading the full book.

   Thank you for your time, and congratulations on publishing such a thought-provoking paper.

   The Infinite Recycling Multiverse (IRM)

   Core ideaIf spacetime is infinite and the laws of nature are the same everywhere, then the processes that produced our Big Bang should also occur elsewhere. Big-Bang–like expansions — bubble universes — would arise throughout spacetime.

   In this picture, the background spacetime is not globally accelerating; rather, acceleration is a property of finite expanding regions within it.

   Evolution

   Bubble universes expand

   Galaxies collapse into central black holes

   Bubbles become dominated by black holes

   Black holes from neighbouring expanded bubbles drift through inter-bubble space and merge, forming increasingly massive progenitor structures.

   If black holes are finite physical systems rather than singularities, extreme conditions in these progenitors may trigger phase transitions, producing new expanding regions of spacetime — new bubble universes.

   Result: No terminal heat death — the process repeats (eternal dynamic equilibrium)

   Cosmological implications

   Horizon problemA finite progenitor with extended duration allows pre-expansion equilibration, potentially removing the need for inflation. 

   Flatness problemCurvature gradients relax toward the near-zero mean curvature of the infinite background

   Dark energy / accelerationMay reflect geometric relaxation of a finite embedded region rather than a fundamental cosmological constant

   Heat deathReplaced by recycling — gravitational collapse seeds new expanding regions

   Physical picture

   Expansion spreads structure outward. Collapse gathers it inward.New bubble universes emerge from the mixed remnants of many earlier ones.

   Entropy is not reversed, but reorganised into new accessible structure.Causal continuity is preserved through successive expansions.

   Key difference from other multiverse models

   Bubble universes are not completely isolated. Matter and structure from different regions can mix through long-term black-hole interactions, allowing new expanding regions to emerge from the combined remnants of many earlier ones.

   I realise this sits outside mainstream approaches, but it attempts to minimise assumptions while addressing several open problems within a single framework.

   Kind regards,

   David J Franks

   The Infinite Recycling Multiverse: Eternal Dynamic Equilibrium

   LikeLike

   Reply
   1. 

      fsyloslab

      July 7, 2026

      Thank you for your comment and your interest in our work.

      LikeLike

      Reply