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1. Modular invariant holomorphic observables

   https://doi.org/10.1016/j.physletb.2024.138600  

   Chen, Mu-Chun; Li, Xueqi; Liu, Xiang-Gan; Medina, Omar; Ratz, Michael (May 2024, Physics Letters B)
2. u-Channel Color Transparency Observables

   https://doi.org/10.3390/physics4020030  

   Huber, Garth M.; Li, Wenliang B.; Cosyn, Wim; Pire, Bernard (June 2022, Physics)

   The paper proposes to study the onset of color transparency in hard exclusive reactions in the backward regime. Guided by the encouraging Jefferson Laboratory (JLab) results on backward π and ω electroproduction data at moderate virtuality Q2, which may be interpreted as the signal of an early scaling regime, where the scattering amplitude factorizes in a hard coefficient function convoluted with nucleon to meson transition distribution amplitudes, the study shows that investigations of these channels on nuclear targets opens a new opportunity to test the appearance of nuclear color transparency for a fast-moving nucleon. 

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3. An algebra of observables for de Sitter space

   https://doi.org/10.1007/JHEP02(2023)082  

   Chandrasekaran, Venkatesa; Longo, Roberto; Penington, Geoff; Witten, Edward (February 2023, Journal of High Energy Physics)

   A bstract We describe an algebra of observables for a static patch in de Sitter space, with operators gravitationally dressed to the worldline of an observer. The algebra is a von Neumann algebra of Type II 1 . There is a natural notion of entropy for a state of such an algebra. There is a maximum entropy state, which corresponds to empty de Sitter space, and the entropy of any semiclassical state of the Type II 1 algebras agrees, up to an additive constant independent of the state, with the expected generalized entropy S gen = ( A/ 4 G N ) + S out . An arbitrary additive constant is present because of the renormalization that is involved in defining entropy for a Type II 1 algebra. 

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4. PATOKA: Simulating Electromagnetic Observables of Black Hole Accretion

   https://doi.org/10.3847/1538-4365/ac582e  

   Wong, George N.; Prather, Ben S.; Dhruv, Vedant; Ryan, Benjamin R.; Mościbrodzka, Monika; Chan, Chi-kwan; Joshi, Abhishek V.; Yarza, Ricardo; Ricarte, Angelo; Shiokawa, Hotaka; et al (April 2022, The Astrophysical Journal Supplement Series)

   Abstract The Event Horizon Telescope (EHT) has released analyses of reconstructed images of horizon-scale millimeter emission near the supermassive black hole at the center of the M87 galaxy. Parts of the analyses made use of a large library of synthetic black hole images and spectra, which were produced using numerical general relativistic magnetohydrodynamics fluid simulations and polarized ray tracing. In this article, we describe thePATOKApipeline, which was used to generate the Illinois contribution to the EHT simulation library. We begin by describing the relevant accretion systems and radiative processes. We then describe the details of the three numerical codes we use,iharm,ipole, andigrmonty, paying particular attention to differences between the current generation of the codes and the originally published versions. Finally, we provide a brief overview of simulated data as produced byPATOKAand conclude with a discussion of limitations and future directions. 

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5. From orbitals to observables and back

   https://doi.org/10.1063/5.0018597  

   Krylov, Anna I. (August 2020, The Journal of Chemical Physics)