Holographic Principles Enable Constraints on Quantum Gravity and Long-lived Scalar Fields

The search for a consistent theory of quantum gravity represents one of the most significant challenges in modern physics, and the Swampland Program seeks to define the boundaries of viable effective field theories. Sudhaker Upadhyay, from K. L. S. College, Magadh University, Alexander A. Reshetnyak from Tomsk State Pedagogical University and National Research Tomsk Polytechnic University, and Pavel Yu. Moshin and Ricardo A. Castro from Universidade Federal de Pernambuco, investigate these boundaries using insights from holography, a framework that connects gravity to quantum field theories. Their work explores how fundamental holographic principles, including constraints on energy conditions and the behaviour of quantum fields, translate into limitations on the types of gravitational theories that can consistently describe our universe. By establishing a geometric connection between holography and the Swampland, this research offers new perspectives on the search for a complete theory of quantum gravity and sheds light on the possible absence of stable, accelerating universes.

String Theory, Swampland, and Quantum Gravity Landscapes

This extensive collection of research explores the frontiers of theoretical physics, particularly focusing on string theory and quantum gravity. Researchers are actively exploring the ‘swampland’, identifying criteria that effective field theories must satisfy to align with fundamental principles of quantum gravity, and investigating cosmology, dark matter, and the nature of singularities. The bibliography encompasses studies of the holographic principle, quantum effects in strong gravitational fields, and the search for a complete ultraviolet completion of effective field theories. Ultimately, this research aims to identify a fundamental theory that describes physics at the highest energies, resolving the limitations of current effective field theories.

Holographic Consistency and the Swampland Program

This work investigates the relationship between the Swampland Program and the holographic principle, demonstrating how constraints on effective field theories translate into conditions for holographic consistency. This establishes a holographic landscape and defines the boundaries of the swampland. Further investigation reveals how the Distance Conjecture manifests in the dual conformal field theory as an accumulation of light operators, signaling a breakdown of bulk locality. Researchers also explore the implications for de Sitter space, suggesting the absence of stable or metastable de Sitter space in quantum gravity arises from holographic consistency conditions. By establishing a precise dictionary between bulk fields and boundary operators, scientists interpret Swampland bounds as emergent consequences of fundamental holographic principles, providing a deeper understanding of the quantum structure of spacetime and the limits of effective field theories.

Holographic Geometry Unifies Swampland Conjectures

This work explores the profound connection between the Swampland Program and holography, revealing how consistency conditions in holographic systems map onto constraints within effective field theories. Researchers demonstrate that holographic principles provide a geometric realization of Swampland bounds, particularly concerning scalar field potentials and the absence of long-lived de Sitter vacua. The team synthesized these results into a unified holographic inequality, encapsulating the Distance, Weak Gravity, and de Sitter conjectures. This inequality suggests that all Swampland conjectures emerge from a single geometric condition guaranteeing the convexity and positivity of the holographic effective action.

Measurements confirm a direct link between entanglement and the emergence of spacetime geometry. The team showed that fluctuations in the bulk metric are emergent collective degrees of freedom arising from entanglement perturbations in the boundary theory. Specifically, the field-space metric can be expressed holographically as a Fisher information metric on the manifold of boundary density matrices, revealing that moduli-space geometry is an emergent information metric determined entirely by boundary entanglement properties. Combining this with the Distance Conjecture, researchers found that the relative entropy between distant vacua decays exponentially, demonstrating that trans-Planckian field excursions correspond to exponentially indistinguishable boundary states.

Further analysis reveals that the modular Hamiltonian imposes constraints on energy flux in the boundary theory. Positivity of relative entropy necessitates a condition that, through holographic reconstruction, maps to the bulk null energy condition, demonstrating a sharpened version of the refined de Sitter bound. These findings suggest that Swampland bounds are not merely theoretical constructs, but fundamental consequences of the principle of emergence and universal information-theoretic properties of holographic systems.

Holographic Emergence Bound Constrains Quantum Gravity

This work presents a unified holographic framework for understanding the Swampland conjectures, which aim to identify consistent theories of quantum gravity and distinguish them from those that are not viable. Researchers demonstrated how conjectures concerning scalar field potentials and the absence of stable de Sitter space emerge from fundamental principles of holographic consistency, linking bulk gravitational dynamics to boundary conformal field theory. Specifically, the team recast traditional Swampland conjectures in terms of moduli-space geometry and effective potentials, revealing their connection to spectral, entanglement, and energy positivity conditions in the boundary theory. The analysis culminated in a new inequality, the Holographic Emergence Bound, which encapsulates existing Swampland conjectures as limiting cases of a single holographic consistency condition.

This bound arises from requiring positivity of relative entropy, unitary modular flow, and monotonic evolution of holographic entanglement entropy, suggesting it is not an empirical conjecture but a theorem rooted in holographic principles. The findings establish a deep connection between the Swampland program and holography, proposing they are complementary aspects of a single physical principle: the finiteness and consistency of quantum information within gravitational systems. The Distance Conjecture, de Sitter Conjecture, and Weak Gravity Conjecture all emerge as projections of holographic information geometry, highlighting a fundamental link between information-theoretic laws and geometric constraints in gravity. Researchers acknowledge that further investigation is needed to fully explore the implications of the Holographic Emergence Bound and its connection to other areas of theoretical physics.