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1. Dressing bulk fields in AdS3

   https://doi.org/10.1007/JHEP10(2020)189  

   Kabat, Daniel; Lifschytz, Gilad (October 2020, Journal of High Energy Physics)

   null (Ed.)

   A bstract We study a set of CFT operators suitable for reconstructing a charged bulk scalar field ϕ in AdS 3 (dual to an operator $$ \mathcal{O} $$ O of dimension ∆ in the CFT) in the presence of a conserved spin- n current in the CFT. One has to sum a tower of smeared non-primary scalars $$ {\partial}_{+}^m{J}^{(m)} $$ ∂ + m J m , where J ( m ) are primaries with twist ∆ and spin m built from $$ \mathcal{O} $$ O and the current. The coefficients of these operators can be fixed by demanding that bulk correlators are well-defined: with a simple ansatz this requirement allows us to calculate bulk correlators directly from the CFT. They are built from specific polynomials of the kinematic invariants up to a freedom to make field redefinitions. To order 1/ N this procedure captures the dressing of the bulk scalar field by a radial generalized Wilson line. 

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2. Material profile influences in bulk-heterojunctions

   https://doi.org/10.1002/polb.23564  

   Roehling, John D.; Rochester, Christopher W.; Ro, Hyun Wook; Wang, Peng; Majewski, Jaroslaw; Batenburg, K. Joost; Arslan, Ilke; Delongchamp, Dean M.; Moulé, Adam J. (October 2014, Journal of Polymer Science Part B: Polymer Physics)
3. Boundary-bulk relation in topological orders

   https://doi.org/10.1016/j.nuclphysb.2017.06.023  

   Kong, Liang; Wen, Xiao-Gang; Zheng, Hao (September 2017, Nuclear Physics B)
4. Discrete bulk reconstruction

   https://doi.org/10.1007/JHEP04(2023)037  

   Aaronson, Scott; Pollack, Jason (April 2023, Journal of High Energy Physics)

   A bstract According to the AdS/CFT correspondence , the geometries of certain spacetimes are fully determined by quantum states that live on their boundaries — indeed, by the von Neumann entropies of portions of those boundary states. This work investigates to what extent the geometries can be reconstructed from the entropies in polynomial time . Bouland, Fefferman, and Vazirani (2019) argued that the AdS/CFT map can be exponentially complex if one wants to reconstruct regions such as the interiors of black holes. Our main result provides a sort of converse: we show that, in the special case of a single 1D boundary divided into N “atomic regions”, if the input data consists of a list of entropies of contiguous boundary regions, and if the entropies satisfy a single inequality called Strong Subadditivity, then we can construct a graph model for the bulk in linear time. Moreover, the bulk graph is planar, it has O ( N 2 ) vertices (the information-theoretic minimum), and it’s “universal”, with only the edge weights depending on the specific entropies in question. From a combinatorial perspective, our problem boils down to an “inverse” of the famous min-cut problem: rather than being given a graph and asked to find a min-cut, here we’re given the values of min-cuts separating various sets of vertices, and need to find a weighted undirected graph consistent with those values. Our solution to this problem relies on the notion of a “bulkless” graph, which might be of independent interest for AdS/CFT. We also make initial progress on the case of multiple 1D boundaries — where the boundaries could be connected via wormholes — including an upper bound of O ( N 4 ) vertices whenever an embeddable bulk graph exists (thus putting the problem into the complexity class NP). 

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5. Unusual superparamagnetic behavior in bulk Ba0.198La0.784Ti0.096Fe0.8O3-δ

   https://doi.org/10.1016/j.materresbull.2020.111187  

   El Bachraoui, Fatima; Tamraoui, Youssef; Louihi, Said; Alami, Jones; Shahbazian-Yassar, Reza; Yuan, Yifei; Amine, Khalil; Manoun, Bouchaib (May 2021, Materials Research Bulletin)

   null (Ed.)