Concept record · Atlas v1.2.0
Extra dimensions
Active researchWhat the term means here
Spatial dimensions beyond the three we observe, required by the consistency conditions of string and M-theory. They must be hidden from current experiment, either by being very small or by some other mechanism.
Why it matters to this question
The size and shape of the extra dimensions determine the four-dimensional physics you get, including the vacuum energy. The de Sitter problem is largely a problem about controlling that geometry.
What this does not establish
No extra dimension has been observed. Torsion-balance experiments find no deviation from the gravitational inverse-square law down to roughly 52 micrometres, which constrains but does not exclude mesoscopic scenarios.
Claims bearing on this concept · 2
- ds-011
The Dark Dimension scenario ties the dark-energy scale to a Kaluza-Klein scale via the AdS distance conjecture, predicting a single extra dimension of roughly micron size.
- ds-012
Torsion-balance experiments report no deviation from the gravitational inverse-square law down to separations of about 52 micrometres.
Sources used for this record · 3
- The Dark Dimension and the SwamplandarXiv:2205.12293
- New Test of the Gravitational 1/r² Law at Separations down to 52 μmarXiv:2002.11761
- Tests of the Gravitational Inverse-Square Law below the Dark-Energy Length Scalehep-ph/0611184