Free Carrollian quantum field theories admit well-defined vacuum and KMS states via algebraic methods, with massless theories requiring nonregular states whose Hilbert spaces factorize into Fock and nonseparable zero-mode sectors relevant for flat space holography.
Rigorous steps towards holography in asymptotically flat spacetimes
6 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
Scalar QFT on the boundary $\Im^+$ at null infinity of a general asymptotically flat 4D spacetime is constructed using the algebraic approach based on Weyl algebra associated to a BMS-invariant symplectic form. The constructed theory is invariant under a suitable unitary representation of the BMS group with manifest meaning when the fields are interpreted as suitable extensions to $\Im^+$ of massless minimally coupled fields propagating in the bulk. The analysis of the found unitary BMS representation proves that such a field on $\Im^+$ coincides with the natural wave function constructed out of the unitary BMS irreducible representation induced from the little group $\Delta$, the semidirect product between SO(2) and the two dimensional translational group. The result proposes a natural criterion to solve the long standing problem of the topology of BMS group. Indeed the found natural correspondence of quantum field theories holds only if the BMS group is equipped with the nuclear topology rejecting instead the Hilbert one. Eventually some theorems towards a holographic description on $\Im^+$ of QFT in the bulk are established at level of $C^*$ algebras of fields for strongly asymptotically predictable spacetimes. It is proved that preservation of a certain symplectic form implies the existence of an injective $*$-homomorphism from the Weyl algebra of fields of the bulk into that associated with the boundary $\Im^+$. Those results are, in particular, applied to 4D Minkowski spacetime where a nice interplay between Poincar\'e invariance in the bulk and BMS invariance on the boundary at $\Im^+$ is established at level of QFT. It arises that the $*$-homomorphism admits unitary implementation and Minkowski vacuum is mapped into the BMS invariant vacuum on $\Im^+$.
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Proves mass decomposition theorem for spacetime inner product via fermionic signature and flux operators for Dirac equation in Reissner-Nordström spacetime in horizon-penetrating coordinates, computes spectra, constructs Hadamard fermionic projector.
Scalar, vector, and tensor spherical harmonics on dS3 are constructed with explicit antipodal relationships between past and future asymptotic data, even with sources, plus decomposition theorems for tensors obeying inhomogeneous wave equations.
Develops worldsheet sigma model for fundamental strings in critical type IIA limit showing nodal singularities and derives T-duality web unifying decoupling limits including ambitwistor and Carrollian strings.
A 3d sourced conformal Carrollian field theory is proposed to holographically capture 4d flat gravity kinematics, with Ward identities matching 2d celestial CFT after relating operators.
Lecture notes that build the BMS group from prerequisites to applications in soft theorems, memory effects, and new material on asymptotic conformal Killing horizons.
citing papers explorer
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Carrollian quantum states and flat space holography
Free Carrollian quantum field theories admit well-defined vacuum and KMS states via algebraic methods, with massless theories requiring nonregular states whose Hilbert spaces factorize into Fock and nonseparable zero-mode sectors relevant for flat space holography.
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The Fermionic Signature Operator in the Reissner-Nordstr\"om Geometry in Horizon-Penetrating Coordinates
Proves mass decomposition theorem for spacetime inner product via fermionic signature and flux operators for Dirac equation in Reissner-Nordström spacetime in horizon-penetrating coordinates, computes spectra, constructs Hadamard fermionic projector.
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Scalar, vector and tensor fields on $dS_3$ with arbitrary sources: harmonic analysis and antipodal maps
Scalar, vector, and tensor spherical harmonics on dS3 are constructed with explicit antipodal relationships between past and future asymptotic data, even with sources, plus decomposition theorems for tensors obeying inhomogeneous wave equations.
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Worldsheet Formalism for Decoupling Limits in String Theory
Develops worldsheet sigma model for fundamental strings in critical type IIA limit showing nodal singularities and derives T-duality web unifying decoupling limits including ambitwistor and Carrollian strings.
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Carrollian Perspective on Celestial Holography
A 3d sourced conformal Carrollian field theory is proposed to holographically capture 4d flat gravity kinematics, with Ward identities matching 2d celestial CFT after relating operators.
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Lectures on the Bondi--Metzner--Sachs group and related topics in infrared physics
Lecture notes that build the BMS group from prerequisites to applications in soft theorems, memory effects, and new material on asymptotic conformal Killing horizons.