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1. Generalized Veneziano and Virasoro amplitudes

   https://doi.org/10.1007/JHEP04(2023)031  

   Geiser, Nicholas ; Lindwasser, Lukas W. ( April 2023 , Journal of High Energy Physics)

   We analyze so-called generalized Veneziano and generalized Virasoro amplitudes. Under some physical assumptions, we find that their spectra must satisfy an over-determined set of non-linear recursion relations. The recursion relation for the generalized Veneziano amplitudes can be solved analytically and yields a two-parameter family which includes the Veneziano amplitude, the one-parameter family of Coon amplitudes, and a larger two-parameter family of amplitudes with an infinite tower of spins at each mass level. In the generalized Virasoro case, the only consistent solution is the string spectrum.

    

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2. Rotational Study of 5:3 and 7:4 Resonant Objects within the Main Classical Trans-Neptunian Belt

   https://doi.org/10.3847/PSJ/ad2933  

   Thirouin, Audrey ; Sheppard, Scott S. ( April 2024 , The Planetary Science Journal)

   The 5:3 and 7:4 mean motion resonances of Neptune are at 42.3 and 43.7 au, respectively, and overlap with objects in the classical trans-Neptunian belt (Kuiper Belt). We report the complete/partial lightcurves of 13 and 14 trans-Neptunian objects (TNOs) in the 5:3 and 7:4 resonances, respectively. We report a most likely contact binary in the 7:4 resonance, 2013 FR₂₈, with a periodicity of 13.97 ± 0.04 hr and a lightcurve amplitude of 0.94 ± 0.02 mag. With a V-/U-shaped lightcurve, 2013 FR₂₈has one of the largest well-sampled TNO amplitudes observed with ground-based observations, comparable to the well-determined contact binary 2001 QG₂₉₈. 2013 FR₂₈has a mass ratioq∼ 1 with a densityρ∼ 1 g cm⁻³. We find several objects with large amplitudes and classify 2004 SC₆₀, 2006 CJ₆₉, and 2013 BN₈₂as likely contact binaries and 2001 QF₃₃₁, 2003 YW₁₇₉, and 2015 FP₃₄₅as likely elongated objects. We observe the 17:9 resonant or classical object 2003 SP₃₁₇that we classify as a likely contact binary. A lower estimate of 10%–50% and 20%–55% for the fraction of (nearly) equal-sized contact binaries is calculated in the 5:3 and 7:4 resonances, respectively. Surface colors of 2004 SC₆₀, 2013 BN₈₂, 2014 OL₃₉₄, and 2015 FP₃₄₅have been obtained. Including these colors with ones from the literature reveals that elongated objects and contact binaries share the same ultrared surface color, except Manwë–Thorondor and 2004 SC₆₀. Not only are the colors of the 7:4 and 5:3 TNOs similar to the cold classicals, but we demonstrate that the rotational properties of the 5:3 and 7:4 resonants are similar to those of the cold classicals, inferring a clear link between these subpopulations.

    

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3. Spectrum of quantum KdV hierarchy in the semiclassical limit

   https://doi.org/10.1007/JHEP09(2022)169  

   Dymarsky, Anatoly ; Kakkar, Ashish ; Pavlenko, Kirill ; Sugishita, Sotaro ( September 2022 , Journal of High Energy Physics)

   We employ semiclassical quantization to calculate spectrum of quantum KdV charges in the limit of large central chargec. Classically, KdV chargesQ_2n−1generate completely integrable dynamics on the co-adjoint orbit of the Virasoro algebra. They can be expressed in terms of action variablesI_k, e.g. as a power series expansion. Quantum-mechanically this series becomes the expansion in 1/c, while action variables become integer-valued quantum numbersn_i. Crucially, classical expression, which is homogeneous inI_k, acquires quantum corrections that include terms of subleading powers inn_k. At first two non-trivial orders in 1/cexpansion these “quantum” terms can be fixed from the analytic form ofQ_2n−1acting on the primary states. In this way we find explicit expression for the spectrum ofQ_2n−1up to first three orders in 1/cexpansion. We apply this result to study thermal expectation values ofQ_2n−1and free energy of the KdV Generalized Gibbs Ensemble.

    

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4. Photometry of Outer Solar System Objects from the Dark Energy Survey. I. Photometric Methods, Light-curve Distributions, and Trans-Neptunian Binaries

   https://doi.org/10.3847/1538-4365/acf6bf  

   Bernardinelli, Pedro H. ; Bernstein, Gary M. ; Jindal, Nicholas ; Abbott, T. M. C. ; Aguena, M. ; Alves, O. ; Andrade-Oliveira, F. ; Annis, J. ; Bacon, D. ; Bertin, E. ; et al ( October 2023 , The Astrophysical Journal Supplement Series)

   We report the methods of and initial scientific inferences from the extraction of precision photometric information for the >800 trans-Neptunian objects (TNOs) discovered in the images of the Dark Energy Survey (DES). Scene-modeling photometry is used to obtain shot-noise-limited flux measures for each exposure of each TNO, with background sources subtracted. Comparison of double-source fits to the pixel data with single-source fits are used to identify and characterize two binary TNO systems. A Markov Chain Monte Carlo method samples the joint likelihood of the intrinsic colors of each source as well as the amplitude of its flux variation, given the time series of multiband flux measurements and their uncertainties. A catalog of these colors and light-curve amplitudesAis included with this publication. We show how to assign a likelihood to the distributionq(A) of light-curve amplitudes in any subpopulation. Using this method, we find decisive evidence (i.e., evidence ratio <0.01) that cold classical (CC) TNOs with absolute magnitude 6 <H_r< 8.2 are more variable than the hot classical (HC) population of the sameH_r, reinforcing theories that the former form in situ and the latter arise from a different physical population. Resonant and scattering TNOs in thisH_rrange have variability consistent with either the HCs or CCs. DES TNOs withH_r< 6 are seen to be decisively less variable than higher-H_rmembers of any dynamical group, as expected. More surprising is that detached TNOs are decisively less variable than scattering TNOs, which requires them to have distinct source regions or some subsequent differential processing.

    

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5. Numerical Simulations of Tidal Deformation and Resulting Light Curves of Small Bodies: Material Constraints of 99942 Apophis and 1I/‘Oumuamua

   https://doi.org/10.3847/PSJ/acccef  

   Taylor, Aster G. ; Seligman, Darryl Z. ; MacAyeal, Douglas R. ; Hainaut, Olivier R. ; Meech, Karen J. ( May 2023 , The Planetary Science Journal)

   In this paper, we present an open-source software (Simulator of Asteroid Malformation Under Stress,SAMUS) that simulates constant-density, constant-viscosity liquid bodies subject to tidal forces for a range of assumed viscosities and sizes. This software solves the Navier–Stokes equations on a finite-element mesh, incorporating the centrifugal, Coriolis, self-gravitational, and tidal forces. The primary functionality is to simulate the deformation of minor bodies under the influence of tidal forces. It may therefore be used to constrain the composition and physical structure of bodies experiencing significant tidal forces, such as 99942 Apophis and 1I/‘Oumuamua. We demonstrate thatSAMUSwill be useful to constrain the material properties of Apophis during its near-Earth flyby in 2029. Depending on the material properties, Apophis may experience an area change of up to 0.5%, with similar effects on the photometric brightness. We also applySAMUSto constrain the material dynamic viscosity of 1I/‘Oumuamua, the first interstellar object discovered traversing the inner solar system. ‘Oumuamua experienced a close approach to the Sun at perihelion (q≃ 0.25 au) during which there were significant tidal forces that may have caused deformation of the body. This deformation could have lead to observable changes in the photometric light curve based on the material properties. The application ofSAMUSto produce synthetic observations which incorporate tidal deformation effects demonstrates that no deformation—an infinite dynamic viscosity—best reproduces the photometric data. While these results indicate that ‘Oumuamua did not experience significant tidal deformation, a sophisticated model incorporating nonprincipal axis rotation is necessary to conclusively analyze both ‘Oumuamua and Apophis.

    

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