Universes in Wine Glasses: How Wormholes Reconciled the Irreconcilable ✛ ✎ ✦

Original: "Birth of Inflationary Universes via Wineglass Wormholes and their No-Boundary Relatives"

· George Lavrelashvili, Jean-Luc Lehners

arXiv:2605.10548v1 · 2026-05-11 · arXiv non-exclusive · independent analysis · 3 min

Quantum wormholes whose scale factor resembles a wine glass have shown that tunneling from primordial foam and birth from 'nothing' à la Hawking are one mechanism, two phases of the same process.

Cosmology has long sought a loophole behind the Big Bang. Inflation, proposed by Alan Guth, stretches and smooths out primordial inhomogeneities, but what lit the fuse itself? Until recently, physicists vacillated between two extremes: either a newborn universe emerges from the frothing foam of an eternal cosmos through a wormhole, or it arises from pure 'nothing'—via a no-boundary instanton, as taught by Stephen Hawking and James Hartle. The first picture is tunneling between spaces, the second — creation without an external stage. A new class of solutions shows: it's not a choice, but two poles of a single spectrum.

The central image is a wine glass. Mathematically, this is the profile of the scale factor a(τ), depending on Euclidean time τ. The wide bowl corresponds to de Sitter expansion — the future inflationary universe. The thin stem is the wormhole throat, where spacetime curvature soars to extreme values. The flat base symbolizes the distant asymptotics, from which (or to which?) the tunneling geometry departs. To carve such a glass from Einstein's equations, the authors added matter: a self-interacting scalar field with a potential that has a plateau and a minimum, and a charge — axion or magnetic. It's the charge that stabilizes the stem, preventing the throat from pinching off prematurely. Without it, the glass would collapse before giving birth to a universe.

Numerical surprise: The probability of universe creation, proportional to exp(-$S_E$), grows as the charge decreases. The thinner the stem of the glass, the weightier the contribution to the quantum integral. In the limit Q→0, the stem vanishes entirely — the geometry splits into a closed de Sitter sphere and a detached background space. The Euclidean action smoothly transitions to the value -$S_E$ = 12π² / $V_{top}$, which for $V_{top}$=1 (in Planck units) gives about 118.4—a number as if engraved on the gates of creation.

This elegant transition erases the artificial boundary between tunneling and the no-boundary state. From the standpoint of quantum fields and topological fluctuations, numerous histories contribute to the wave function of the Universe, and wine-glass wormholes are a tangible realization of this idea. The next step is to compute the spectrum of primordial perturbations left by such scenarios in the cosmic microwave background and compare it with data from WMAP and Planck satellites. If the signature shows up in subtle statistical anomalies, we'll have a direct window to the very onset of expansion — to the moment when the glass just began to fill with reality.

The characteristic scale of the 'rim' at small charges is about 1.732 in units of the inverse Hubble radius of inflation, while the throat can shrink to 0.1 of that size. At such extreme values of spacetime curvature, classical concepts melt away, giving way to full-blown quantum gravity. Perhaps it is here, in the neck of the glass, that time itself is born.

The prospect is mesmerizing. If wine-glass wormholes are realistic, they naturally solve the initial conditions problem for inflation and embed eternal inflation within a consistent quantum cosmology. Moreover, they force us to rethink the factorization paradox in AdS/CFT and may offer a key to the measure problem — why, among the countless variants of the multiverse, the one we see is realized. From a wine glass to the fate of the cosmos — one sip of mathematics. And in that sip, there's a hint that our universe is perhaps just one of countless sparks flying out of the neck of a quantum wormhole.

Whole graph →

The scale factor of these wormholes traces the profile of a wine glass: the wide bowl is the future universe, the thin stem is the throat, and the base is the distant asymptotic region. Hence the poetic name physicists gave their solution.

If in 'Interstellar' a wormhole is a portal to another galaxy, here it's a quantum cradle of universes, frozen in Euclidean time.

S_E = 2\pi^2 \int d\tau \left( -3 a \dot{a}^2 + \frac{1}{2} a^3 \dot{\phi}^2 - 3a + a^3 V(\phi) + \frac{Q_a^2}{a^3} + \frac{Q_m^2}{a} \right)

The action determines the weight of a configuration in the path integral: Ψ ∼ exp(-S_E).

-S_{E} = \frac{12\pi^2}{V_{top}}

For V_top=1 (in Planck units), the weight is about 118.4, which is the limit for low-charge wine-glass wormholes.

Scientists

Alan Guth Alexander Friedmann Andrei Linde Georges Lemaître James Peebles Bernhard Riemann

Concepts

eternal inflation inflationary cosmology Wormhole inflaton inflation inflationary gravitational waves gravitational instanton traversable wormhole de sitter space cosmological collider planck time exponential growth spacetime foam throat cosmic expansion stellar nursery instanton starobinsky inflation spacetime emergence quantum ripples

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Universes in Wine Glasses: How Wormholes Reconciled the Irreconcilable ✛ ✎ ✦