Wormhole Nucleation from Anti-de Sitter

2024 / 2026Panos Betzios, Olga Papadoulaki, George Lavrelashvili, Jean-Luc LehnersSpeculative4 primary sources, 2 established Reviewed October 17, 2026

Our universe nucleates out of an older spacetime through a Euclidean wormhole, then inflates.

Visualisation · Quantum Tunneling Origin

anti-de Sitter space: A spacetime of constant negative curvature, the natural setting for the AdS/CFT correspondence. Distinct from our universe, which has positive cosmological constant (de Sitter), but the framework provides the cleanest testing ground for holographic ideas.
inflation: A brief burst of accelerating expansion in the very early universe, smoothing out and stretching whatever existed before.
cosmic microwave background: The faint, uniform glow of light released about 380,000 years after the Big Bang, when the universe first became transparent.

§1 · The claim, in one sentence

A wave function for the universe in which a Euclidean wormhole, anchored in an anti-de Sitter region, gives birth to an expanding universe that begins with inflation.

§2 · Why it might be true

Betzios and Papadoulaki proposed in 2024 a new wave function for the universe. Our universe does not begin from nothing. It nucleates out of a pre-existing anti-de Sitter space through a Euclidean wormhole.

The wormhole has a widest point, and that point turns into an expanding universe once time becomes real. The new universe naturally starts with a phase of inflation.

In 2026 Lavrelashvili and Lehners showed that as the wormhole's charge shrinks to zero, its throat pinches off. What remains is a Hartle-Hawking no-boundary instanton, so both pictures belong to one family of solutions.

The family stance

Either literally nothing (Vilenkin), or a state without a temporal boundary (Hartle-Hawking), or a zero-energy quantum fluctuation (Tryon). All deny that a classical "before" makes sense.

§2.5 · Evidence

Betzios and Papadoulaki (2024) found that this wave function can favour a long inflationary phase, a known weak point of the original no-boundary proposal.
Lavrelashvili and Lehners (2026) built explicit wormhole solutions held open by axion or magnetic fields and showed how they connect to no-boundary instantons.
Several independent groups took up the idea within two years, studying its quantum corrections, its consistency conditions and its links to other quantum cosmology proposals.

§3 · What you'd need to test it

A small shift and faint oscillations in the cosmic microwave background on the largest angular scales, with a size set by the wormhole's charge
Short-wavelength fluctuations identical to those of standard inflation, so the signature appears only on the largest scales
Wormholes with small charge give a longer phase of inflation than wormholes with large charge

§4 · Where it breaks

Lavrelashvili and Lehners find that no-boundary instantons still dominate the overall probability, which weakens the case that wormholes are the preferred beginning.
The universe needs a parent anti-de Sitter or flat region to emerge from, which moves the question of origins back one step.
The predicted signal sits on the largest scales of the sky, where there are too few independent patches to measure it precisely.

Go deeper

Betzios and Papadoulaki compute the Euclidean path integral with asymptotically anti-de Sitter boundary conditions instead of the no-boundary condition. The semiclassical saddle is a reflection-symmetric half-wormhole whose scale factor has a local maximum on the surface of symmetry. Analytically continued to Lorentzian signature at that surface, the geometry expands. Because the Euclidean past is asymptotically AdS, the authors suggest that inflating cosmologies and their perturbations might be described holographically.

Lavrelashvili and Lehners call these geometries wineglass wormholes and construct them numerically with a self-interacting scalar plus either an axionic or a magnetic charge. In the zero-charge limit the throat pinches off in a topology-changing transition, leaving the background spacetime and a disconnected no-boundary instanton. The same analysis resolves the long-known puzzle that the action of wineglass wormholes can become negative. A follow-up preprint finds that the quantum state these wormholes prepare matches the Bunch-Davies vacuum for short-wavelength modes but deviates on large scales, by an amount that depends on the charge.

▸§5 · Who built it, and when(4 sources, 2 established, 2 needs verification)

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