Obied, Vafa Propose 1-Micron Dark Dimension Linking Dark Energy and Dark Matter
Updated
Updated · Quanta Magazine · Jun 22
Obied, Vafa Propose 1-Micron Dark Dimension Linking Dark Energy and Dark Matter
1 articles · Updated · Quanta Magazine · Jun 22
Summary
A July 2025 paper by Georges Obied, Cumrun Vafa, Alek Bedroya and David Wu says a roughly 1-micron extra “dark dimension” could connect dark energy and dark matter in a way consistent with DESI observations.
The model treats dark matter as massive gravitons leaking into that dimension, so changes in the dimension’s size would make both dark energy density and dark matter mass decline together over time.
DESI data from 2024 and a larger 2025 follow-up suggested dark energy is not constant and may have peaked about 2 billion years ago, pushing theorists toward coupled dark-sector explanations instead of standalone dark energy.
Related interaction models also aim to ease the Hubble tension—the roughly 9% gap between early- and late-universe expansion-rate measurements—by allowing energy exchange between dark matter and dark energy.
The theory remains unproven, but it yields astrophysical tests: a proposed extra long-range dark-matter force still sits below an observational upper bound set by 2006 tidal-tail studies.
As rival theories clash, will the universe’s greatest mystery be solved by a unified dark sector or by rewriting gravity itself?
Launching this year, will the Roman telescope prove that 95% of our universe is one unified, interacting dark entity?
Dynamic Dark Energy and the Dark Dimension: How DESI’s Latest Results Challenge ΛCDM and Point to New Physics from String Theory
Overview
The universe is expanding faster and faster, a process driven by dark energy. Traditionally, scientists believed dark energy was a constant force, as described by the Lambda-CDM model. However, new results from the DESI project, which used a huge and precise dataset to measure baryon acoustic oscillations, suggest that dark energy might actually change over time. These findings challenge the old assumption and show that dark energy could evolve as the universe grows. This discovery opens the door to new physics and deeper questions about what makes up our universe.