Researchers have published a study in Physical Review Letters demonstrating a mathematically rigorous connection between quantum information and gravity. Using quantum relative entropy, the authors show that Einstein's equations describing how matter curves spacetime can be derived from quantum informational principles, advancing the long-standing search for a unified theory of quantum gravity.
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Findings from a body of new studies point to a fundamental link between gravity and quantum information, with the geometry of spacetime appearing to arise from how quantum fields encode and organise data. Under general relativity, the framework Albert Einstein developed, the pull of gravity arises not from a force acting between objects but from the way mass and energy bend the fabric of spacetime itself.
At the subatomic scale, quantum theory governs how matter and energy behave. How physicists might eventually reconcile the two frameworks stands as one of the field's deepest unresolved questions.
The findings point toward gravity being a derived property rather than a foundational force — one that a deeper layer of physical reality may produce. Appearing in Physical Review Letters, the paper traces a thermodynamic path back to general relativity by drawing on advanced mathematical tools that treat quantum information as a foundation for understanding the structure of spacetime.
Both the published paper and extended discussions with its authors point to quantum relative entropy as the analytical tool behind their tentative findings on how gravity may have originated. Their work rests on a proposition that gravity and space, rather than standing as bedrock properties of the physical world, take shape from underlying quantum processes.
Drawing on quantum relative entropy — a tool from quantum information theory that measures how distinguishable one quantum state is from another, rather than leaning on classical entropy concepts — the research team demonstrated that this quantity, when assessed at a horizon (a spacetime boundary past which no information can travel outward), equals the energy passing through that boundary. Combined with the established connection between entropy and horizon area that Bekenstein and Hawking laid out, that equivalence yields the governing equations for how quantum matter produces curvature in spacetime, according to Dr. Albert Much, an Assistant Professor working across Quantum Field Theory and General Relativity and one of the paper's co-authors.
The quantum vacuum — the condition physicists label as empty space — behaves much as the ocean's surface does: neither achieves true stillness, each sustaining a ceaseless, low-level agitation that never fully subsides. Propagation across that surface encodes a quantum state, while relative entropy quantifies how readily one wave pattern can be told apart from the fluctuating baseline beneath it.
How much the findings matter hinges on whether the underlying proof introduces ideas that are genuinely without precedent, the paper notes. Those researchers themselves acknowledge that the theoretical groundwork connecting information science to gravitational physics had taken shape through earlier contributions predating their own.
The team behind the study notes that the connection was conveyed largely through physical intuition and informal reasoning, stopping short of the formal derivations and proofs that a fully rigorous mathematical treatment would demand. Thermodynamic analogies drawn from classical physics had long served as the primary bridge linking entropy to gravitational theory.
The paper's authors describe their derivation as resting on mathematically rigorous, well-defined quantities rather than the heuristic arguments that preceded it — a foundation they say lends weight to the proposition that spacetime and gravity may arise from more fundamental quantum-information principles. Dr. Much noted that the precise quantum conception of information could take the place of earlier approximations as part of a broader effort to develop a theory of quantum gravity.
The geometry of spacetime may be shaped by how distinguishable quantum states are from one another, according to Dr. Much, who described gravitational equations in their quantum-corrected form as derivable from quantum information principles. He drew an analogy in which matter acts as the initial disturbance on a string, spacetime serves as the string itself, and the resulting vibration corresponds to Einstein's equations. The broader framework of quantum field theory in curved spacetime, treating quantum matter against a gravitational background, is regarded by researchers in the field as a foundational step on the path toward a full theory of quantum gravity.
Philipp Dorau, a theoretical physicist at Leipzig University's Institute for Theoretical Physics, noted that the team's findings point toward a deeper underlying connection — one in which the curvature of spacetime at a local level appears tied to quantum information — adding that "most of the ingredients for our work have been known for decades." Dorau noted that physicists had spent considerable time examining quantum matter behaviour near horizons — including those surrounding black holes — along with the thermal characteristics of empty space, and that advances in understanding relative entropy had supplied the connective thread linking quantum information, thermodynamics, and gravity. He added that though the work carries no immediate practical applications, its contribution rests in broadening the foundational picture of how nature operates.
Such groundwork has, at times, shaped outcomes that unfolded over years or decades, though the extent of that influence has varied. Quantum information — the conceptual backbone of Dr. Much's work — provides the foundational layer on which quantum computing and related fields are built, he noted, drawing a comparison with general relativity, a theoretical construct that migrated from academic abstraction into practical use cases such as GPS navigation.
Subject to confirmation, those findings — assuming they withstand scrutiny and are extended through further research — may help address a persistent divide at the heart of modern physics: the as-yet-unresolved incompatibility between quantum mechanics, which describes the behaviour of matter at subatomic scales, and the theory of gravity that Einstein set down more than a century ago. In their framework, gravity is positioned not as an independent foundational force but as something derived from deeper underlying principles.
The data, taken together, draw a picture in which the geometric fabric of space and time arises from the deeper informational structure that governs quantum reality.
The team's stated goal is to extend the work into broader territory — covering varied forms of quantum matter, more general quantum states, and light-like surfaces that occupy a central position in black-hole physics — while Dr. Much noted that efforts are under way to apply the framework to full quantum gravity, with the connection identified in this research expected to serve as a testing ground for competing theories in that field. Noting that upcoming work would centre on constructing the quantum component insertable into one side of those equations to determine whether Einstein's field equations, along with their expected corrections, emerge on the other side, he described the team's broader ambition as establishing how much of gravitational theory can be derived purely from quantum information — a question whose answer, they believe, could point the way toward a unified theory of quantum gravity.