# Araya, Esper, Jia, Kulaxizi, Parnachev ## Bulkcone Singularities and Complex Geodesics \[Links: [arXiv](https://arxiv.org/abs/2602.12893), [PDF](https://arxiv.org/pdf/2602.12893)\] \[Abstract: [[0512 Thermal correlators|Thermal correlators]] in holographic CFTs on a sphere exhibit [[0163 Bulk cone singularity|bulk-cone singularities]] at points connected by null geodesics in the bulk. The [[0030 Operator product expansion|operator product expansion]] analysis of the stress-tensor sector of the correlator shows that there are analogous singularities at spacelike separation for thermal CFTs on a plane. We show that these are associated with complex null geodesics. There is a phase transition between the real and complex spacelike geodesics underpinning this picture. We also provide a phase-shift calculation of the position of these generalised bulk-cone singularities.\] # Banerjee, Dey, Dhar ## Boundary conformal field theory, holography and bulk locality \[Links: [arXiv](https://arxiv.org/abs/2602.04223), [PDF](https://arxiv.org/pdf/2602.04223)\] \[Abstract: We study bulk locality in a scalar effective field theory (EFT) in AdS background in presence of an end-of-the-world (EOW) brane. The [[0181 AdS-BCFT|holographic dual]] description is given in terms of a [[0548 Boundary CFT|boundary conformal field theory]] (BCFT). We compute the two point correlation function of scalar operators in the BCFT using the one-loop [[0109 Witten diagrams|Witten diagrams]] and compare its analytic structure with the constraints imposed by boundary [[0028 Conformal symmetry|conformal symmetry]]. We find that the loop-corrected correlator derived from a local bulk description is not fully compatible with BCFT expectations. This result places nontrivial constraint on bulk locality in holographic BCFT constructions and identifies BCFT correlators as sensitive probes of quantum bulk dynamics in presence of boundaries.\] # Calkins, Pate ## Multi-particle Celestial Operator Product Expansions from the Boundary \[Links: [arXiv](https://arxiv.org/abs/2601.04329), [PDF](https://arxiv.org/pdf/2601.04329)\] \[Abstract: In [[0010 Celestial holography|celestial holography]], scattering particles in four-dimensional asymptotically flat spacetimes are dual to conformal primary field operators on the celestial sphere. Multi-particle celestial operators can be formed from regularized coincident limits of single-particle celestial operators. The singular terms in the [[0030 Operator product expansion|operator product expansion]] of multi-particle operators are shown to be determined entirely by the singular terms in the operator product expansion between single-particle celestial operators, as expected in a standard conformal field theory. Boundary operator product expansions in celestial holography are known to be dual to subtle [[0078 Collinear limit|collinear limits]] of bulk scattering amplitudes. The multi-particle operator product expansions derived from standard conformal-field theoretic techniques are shown to reproduce precisely the results from the corresponding bulk collinear limits in tree-level Yang-Mills and Einstein gravity. Finally, the coefficients of multi-particle celestial operator product expansions are derived from a third complementary method that enforces bulk four-dimensional translational invariance as a global symmetry of the celestial dual. The results of all three methods agree precisely.\] # Czech, Shuai ## Renormalization Group is the principle behind the Holographic Entropy Cone \[Links: [arXiv](https://arxiv.org/abs/2601.02472), [PDF](https://arxiv.org/pdf/2601.02472)\] \[Abstract: We show that every [[0259 Holographic entropy cone|holographic entropy inequality]] can be recast in the form: 'some entanglement wedges reach deeper in the bulk than some other entanglement wedges.' When the inequality is saturated, the two sets of wedges reach equally deep. Because bulk depth geometrizes CFT scales, the inequalities enforce and protect the [[0209 Holographic renormalisation|holographic Renormalization Group]].\] # Johnson, Rodrigues ## Non-perturbative data for Weil-Petersson volumes and intersection numbers using ordinary differential equations \[Links: [arXiv](https://arxiv.org/abs/2601.03351), [PDF](https://arxiv.org/pdf/2601.03351)\] \[Abstract: Recently, a new method was introduced for computing $V_{g,1}(b)$, the Weil-Petersson volumes of the moduli space of Riemann surfaces of genus g with one geodesic boundary of length $b$, various supersymmetric generalizations of them, as well as analogous quantities in intersection theory. The physical setting is the computation of a certain one-point function in a variety of models of 2D gravity for which there is a double-scaled [[0197 Matrix model|random matrix model]] (RMM) description. The method combines perturbative solutions of two ordinary differential equations (ODEs), the Gel'fand-Dikii resolvent equation, and the RMM's string equation. In this paper, we extend the method to extract non-perturbative information about the $V_{g,1}(b)$ (and their analogues) that is naturally contained in the full ODEs, providing an efficient prescription for computing the transseries coefficients of the one-point correlation function, fully incorporating [[0652 ZZ brane|ZZ-brane]] and [[0658 FZZT brane|FZZT-brane]] effects, and for the first time, mixed ZZ-FZZT-effects. We use as a case study the (2,3) [[0583 Minimal string theories|minimal string]], computing perturbative and non-perturbative quantities, comparing them to perturbative results from topological recursion, and to results from the recent non-perturbative topological recursion framework of Eynard [this http URL](http://et.al/). As a particularly powerful further application we provide general predictions for the large order in g growth of $V_{g,1}(b)$, and apply them to [[0050 JT gravity|JT gravity]], finding agreement with known results, and for analogous quantities in $\mathcal{N} {=} 1$ JT supergravity, proving a conjecture of Stanford and Witten. Our predictions yield new growth formulae for the cases of $\mathcal{N} {=} 2$ and $\mathcal{N}{=}4$ JT supergravity.\] # Liu, Ma ## Unifying soft and hard dynamics: The hard current algebra in celestial holography \[Links: [arXiv](https://arxiv.org/abs/2601.10601), [PDF](https://arxiv.org/pdf/2601.10601)\] \[Abstract: Soft current algebras capture the infrared structure of scattering in asymptotically flat spacetimes, but an analogous algebraic description of finite-energy dynamics has been missing. We uncover an infinite-dimensional hard current algebra that encodes finite-energy contributions to scattering and implies novel [[0106 Ward identity|Ward identities]]. The soft current algebras are not independent but arise naturally from the hard ones. This provides a unified algebraic framework underlying quantum theory in flat spacetime.\] # Nakayama ## To boost or not to boost, that's the question \[Links: [arXiv](https://arxiv.org/abs/2602.15275), [PDF](https://arxiv.org/pdf/2602.15275)\] \[Abstract: Or should we talk about [[0251 dS-CFT|dS/CFT]] correspondence or dS/SFT correspondence in cosmological correlators? In non-unitary field theories -- which are conjectured to be dual to cosmological correlators -- scale invariance does not necessarily imply full conformal invariance. While general relativity predicts the emergence of conformal invariance (or boost symmetry in the bulk), various modified theories of gravity suggest only scale invariance, characterized by the absence of bulk boost symmetry. We demonstrate this distinction using Einstein-Aether theory as a canonical example.\]