@article{17078, abstract = {For the emergence of life, the abiotic synthesis of RNA from its monomers is a central step. We found that in alkaline, drying conditions in bulk and at heated air‐water interfaces, 2′,3′‐cyclic nucleotides oligomerised without additional catalyst, forming up to 10‐mers within a day. The oligomerisation proceeded at a pH range of 7–12, at temperatures between 40–80 °C and was marginally enhanced by K+ ions. Among the canonical ribonucleotides, cGMP oligomerised most efficiently. Quantification was performed using HPLC coupled to ESI‐TOF by fitting the isotope distribution to the mass spectra. Our study suggests a oligomerisation mechanism where cGMP aids the incorporation of the relatively unreactive nucleotides C, A and U. The 2′,3′‐cyclic ribonucleotides are byproducts of prebiotic phosphorylation, nucleotide syntheses and RNA hydrolysis, indicating direct recycling pathways. The simple reaction condition offers a plausible entry point for RNA to the evolution of life on early Earth.}, author = {Dass, Avinash Vicholous and Wunnava, Sreekar and Langlais, Juliette and von der Esch, Beatriz and Krusche, Maik and Ufer, Lennard and Chrisam, Nico and Dubini, Romeo C. A. and Gartner, Florian and Angerpointner, Severin and Dirscherl, Christina F. and Rovo, Petra and Mast, Christof B. and Šponer, Judit E. and Ochsenfeld, Christian and Frey, Erwin and Braun, Dieter}, issn = {2570-4206}, journal = {ChemSystemsChem}, number = {1}, publisher = {Wiley}, title = {{RNA oligomerisation without added catalyst from 2′,3′‐cyclic nucleotides by drying at air-water interfaces}}, doi = {10.1002/syst.202200026}, volume = {5}, year = {2023}, } @article{17079, abstract = {We study moments of characteristic polynomials of truncated Haar distributed matrices from the three classical compact groups O(N), U(N) and Sp(2N). For finite matrix size we calculate the moments in terms of hypergeometric functions of matrix argument and give explicit integral representations highlighting the duality between the moment and the matrix size as well as the duality between the orthogonal and symplectic cases. Asymptotic expansions in strong and weak non-unitarity regimes are obtained. Using the connection to matrix hypergeometric functions, we establish limit theorems for the log-modulus of the characteristic polynomial evaluated on the unit circle.}, author = {Serebryakov, Alexander and Simm, Nick and Dubach, Guillaume}, issn = {2010-3271}, journal = {Random Matrices: Theory and Applications}, number = {01}, publisher = {World Scientific Publishing}, title = {{Characteristic polynomials of random truncations: Moments, duality and asymptotics}}, doi = {10.1142/s2010326322500496}, volume = {12}, year = {2023}, } @unpublished{17100, abstract = {Prophet inequalities are a central object of study in optimal stopping theory. A gambler is sent values online, sampled from an instance of independent distributions, in an adversarial, random or selected order, depending on the model. When observing each value, the gambler either accepts it as a reward or irrevocably rejects it and proceeds to observe the next value. The goal of the gambler, who cannot see the future, is maximising the expected value of the reward while competing against the expectation of a prophet (the offline maximum). In other words, one seeks to maximise the gambler-to-prophet ratio of the expectations. The model, in which the gambler selects the arrival order first, and then observes the values, is known as Order Selection. In this model a ratio of 0.7251 has been proved to be attainable for any instance. In very recent work, this has been improved up to 0.7258. If the gambler chooses the arrival order (uniformly) at random, we obtain the Random Order model. The worst case ratio over all possible instances has been extensively studied for at least 40 years. In the recent work aforementioned, through simulations, this ratio has been shown to be at most 0.7254 for the Random Order model, thus establishing for the first time that carefully choosing the order, instead of simply taking it at random, benefits the gambler. We give an alternative, more rigorous proof of this fact, by showing mathematically that in the Random Order model, no algorithm can achieve a ratio larger than 0.7235. This sets a new state-of-the-art hardness for this model, and establishes more formally that there is a real benefit in choosing the order.}, author = {Giambartolomei, Giordano and Frederik Mallmann-Trenn, Frederik Mallmann-Trenn and Saona Urmeneta, Raimundo J}, booktitle = {arXiv}, title = {{Prophet inequalities: Separating random order from order selection}}, doi = {10.48550/arXiv.2304.04024}, year = {2023}, } @article{17379, abstract = {We introduce a computational pipeline for simulating and designing C-shells, a new class of planar-to-spatial deployable linkage structures. A C-shell is composed of curved flexible beams connected at rotational joints that can be assembled in a stress-free planar configuration. When actuated, the elastic beams deform and the assembly deploys towards the target 3D shape. We propose two alternative computational design approaches for C-shells: (i) Forward exploration simulates the deployed shape from a planar beam layout provided by the user. Once a satisfactory overall shape is found, a subsequent design optimization adapts the beam geometry to reduce the elastic energy of the linkage while preserving the target shape. (ii) Inverse design is facilitated by a new geometric flattening method that takes a design surface as input and computes an initial layout of piecewise straight linkage beams. Our design optimization algorithm then calculates the smooth curved beams to best reproduce the target shape at minimal elastic energy. We find that C-shells offer a rich space for design and show several studies that highlight new shape topologies that cannot be achieved with existing deployable linkage structures.}, author = {Becker, Quentin and Suzuki, Seiichi and Ren, Yingying and Pellis, Davide and Panetta, Julian and Pauly, Mark}, issn = {1557-7368}, journal = {ACM Transactions on Graphics}, number = {6}, publisher = {Association for Computing Machinery}, title = {{C-shells: Deployable gridshells with curved beams}}, doi = {10.1145/3618366}, volume = {42}, year = {2023}, } @inbook{17380, abstract = {Deployable gridshells are a class of planar-to-spatial structures that achievea 3D curved geometry by inducing bending on a flat grid of elastic beams. However, theslender nature of these beams often conflicts with the structure’s load-bearing capacity.To address this issue, multiple layers are typically stacked to enhance out-of-planestiffness and prevent stability issues. The primary challenge then lies in deploying suchmulti-layered systems globally, as it requires significant shaping forces for actuation.This paper presents an alternative design approach that involves strategically connect-ing compact-to-volumetric gridshell components using weaving principles to shape athick segmented shell. This innovative approach allows for an incremental construc-tion process based entirely on deployable modules with volumetric configurations thatlocally provide the necessary structural depth for the entire system. To demonstrate thisprinciple, we present the realization of BamX, a research pavilion constructed usingdeployable cylindrical components made from raw bamboo slats. These componentsare interconnected at carefully optimized interlocking woven nodes, resulting in abending-active structural frame that is both strong and exceptionally lightweight. Todetermine the optimal topology and geometry of the pavilion, we employ an integrativecomputational approach that leverages advanced numerical optimization techniques.Our method incorporates a physics-based simulation of the bending and twisting be-havior of the bamboo ribbons. By finding the ideal locations for ribbon crossings, weensure that all external and internal forces are in global equilibrium while minimizingthe mechanical stress experienced by each ribbon. BamX exemplifies how a symbiosisof refined weaving craft and advanced computational modeling enables fascinatingnew opportunities for rethinking deployability in architecture.}, author = {Suzuki, Seiichi and Martin, Alison and Ren, Yingying and Chen, Tzu-Ying and Parascho, Stefana and Pauly, Mark}, booktitle = {Advances in Architectural Geometry 2023}, editor = {Dörfler, Kathrin and Knippers, Jan and Menges, Achim and Parascho, Stefana and Pottmann, Helmut and Wortmann, Thomas}, isbn = {9783111160115}, publisher = {De Gruyter}, title = {{BamX: Rethinking Deployability in Architecture through Weaving}}, doi = {10.1515/9783111162683-016}, year = {2023}, } @article{17381, abstract = {We present an algorithmic approach to discover, study, and design multistable elastic knots. Elastic knots are physical realizations of closed curves embedded in 3-space. When endowed with the material thickness and bending resistance of a physical wire, these knots settle into equilibrium states that balance the forces induced by elastic deformation and self-contacts of the wire. In general, elastic knots can have many distinct equilibrium states, i.e. they are multistable mechanical systems. We propose a computational pipeline that combines randomized spatial sampling and physics simulation to efficiently find stable equilibrium states of elastic knots. Leveraging results from knot theory, we run our pipeline on thousands of different topological knot types to create an extensive data set of multistable knots. By applying a series of filters to this data, we discover new transformable knots with interesting geometric and physical properties. A further analysis across knot types reveals geometric and topological patterns, yielding constructive principles that generalize beyond the currently tabulated knot types. We show how multistable elastic knots can be used to design novel deployable structures and engaging recreational puzzles. Several physical prototypes at different scales highlight these applications and validate our simulation.}, author = {Vidulis, Michele and Ren, Yingying and Panetta, Julian and Grinspun, Eitan and Pauly, Mark}, issn = {1557-7368}, journal = {ACM Transactions on Graphics}, number = {4}, publisher = {Association for Computing Machinery}, title = {{Computational exploration of multistable elastic knots}}, doi = {10.1145/3592399}, volume = {42}, year = {2023}, } @article{17382, abstract = {Elastic surfaces that morph between multiple geometrical configurations are of significant engineering value, with applications ranging from the deployment of space-based photovoltaic arrays, the erection of temporary shelters, and the realization of flexible display systems, to understanding the encapsulation and release of viral RNAs. In general, ensuring that a shape with a planar rest configuration can deploy into a target three-dimensional (3D) shape is a nontrivial problem. Moreover, it is difficult to physically realize the local deformations necessary to achieve such global transformation. Here, we give a tutorial on applying conformal mapping to rationalize the geometrical deformation of several microstructure designs. A conformal map is a function that locally preserves angles and shapes but not lengths: some regions are scaled (enlarged or shrunk) more than others. To transform a planar surface to 3D, we implement uniform local scalings as mechanical deformations. Numerous natural and architected material systems exhibit such behavior, including kirigami, origami, hydrogel, linkage mechanisms, and fabric membranes. The design and fabrication of conformally transformable surfaces is a transdisciplinary challenge involving insights from advanced manufacturing, computational design, material science, and mechanics. By recognizing that many material systems exhibit isotropic deformation, we hope to inspire researchers to adopt conformal mapping in designing next-generation surface-based engineering systems.}, author = {Wang, Yue and Ren, Yingying and Chen, Tian}, issn = {1528-9036}, journal = {Journal of Applied Mechanics}, number = {4}, publisher = {American Society of Mechanical Engineers}, title = {{From kirigami to hydrogels: A tutorial on designing conformally transformable surfaces}}, doi = {10.1115/1.4056350}, volume = {90}, year = {2023}, } @article{17498, abstract = {In recent years, there has been tremendous progress on developing program logics for verifying the correctness of programs in a rich and diverse array of languages. Thus far, however, such logics have assumed that programs are written entirely in a single programming language. In practice, this assumption rarely holds since programs are often composed of components written in different programming languages, which interact with one another via some kind of foreign function interface (FFI). In this paper, we take the first steps towards the goal of developing program logics for multi-language verification. Specifically, we present Melocoton, a multi-language program verification system for reasoning about OCaml, C, and their interactions through the OCaml FFI. Melocoton consists of the first formal semantics of (a large subset of) the OCaml FFI—previously only described in prose in the OCaml manual—as well as the first program logic to reason about the interactions of program components written in OCaml and C. Melocoton is fully mechanized in Coq on top of the Iris separation logic framework.}, author = {Guéneau, Armaël and Hostert, Johannes and Spies, Simon and Sammler, Michael Joachim and Birkedal, Lars and Dreyer, Derek}, issn = {2475-1421}, journal = {Proceedings of the ACM on Programming Languages}, number = {OOPSLA2}, pages = {716--744}, publisher = {Association for Computing Machinery}, title = {{Melocoton: A program logic for verified interoperability between OCaml and C}}, doi = {10.1145/3622823}, volume = {7}, year = {2023}, } @article{17499, abstract = {Much work in formal verification of low-level systems is based on one of two approaches: refinement or separation logic. These two approaches have complementary benefits: refinement supports the use of programs as specifications, as well as transitive composition of proofs, whereas separation logic supports conditional specifications, as well as modular ownership reasoning about shared state. A number of verification frameworks employ these techniques in tandem, but in all such cases the benefits of the two techniques remain separate. For example, in frameworks that use relational separation logic to prove contextual refinement, the relational separation logic judgment does not support transitive composition of proofs, while the contextual refinement judgment does not support conditional specifications. In this paper, we propose Conditional Contextual Refinement (or CCR, for short), the first verification system to not only combine refinement and separation logic in a single framework but also to truly marry them together into a unified mechanism enjoying all the benefits of refinement and separation logic simultaneously. Specifically, unlike in prior work, CCR’s refinement specifications are both conditional (with separation logic pre- and post-conditions) and transitively composable. We implement CCR in Coq and evaluate its effectiveness on a range of interesting examples.}, author = {Song, Youngju and Cho, Minki and Lee, Dongjae and Hur, Chung-Kil and Sammler, Michael Joachim and Dreyer, Derek}, issn = {2475-1421}, journal = {Proceedings of the ACM on Programming Languages}, number = {POPL}, pages = {1121--1151}, publisher = {Association for Computing Machinery}, title = {{Conditional contextual refinement}}, doi = {10.1145/3571232}, volume = {7}, year = {2023}, } @article{17500, abstract = {Prior work on multi-language program verification has achieved impressive results, including the compositional verification of complex compilers. But the existing approaches to this problem impose a variety of restrictions on the overall structure of multi-language programs (e.g. fixing the source language, fixing the set of involved languages, fixing the memory model, or fixing the semantics of interoperation). In this paper, we explore the problem of how to avoid such global restrictions. Concretely, we present DimSum: a new, decentralized approach to multi-language semantics and verification, which we have implemented in the Coq proof assistant. Decentralization means that we can define and reason about languages independently from each other (as independent modules communicating via events), but also combine and translate between them when necessary (via a library of combinators). We apply DimSum to a high-level imperative language Rec (with an abstract memory model and function calls), a low-level assembly language Asm (with a concrete memory model, arbitrary jumps, and syscalls), and a mathematical specification language Spec. We evaluate DimSum on two case studies: an Asm library extending Rec with support for pointer comparison, and a coroutine library for Rec written in Asm. In both cases, we show how DimSum allows the Asm libraries to be abstracted to Rec-level specifications, despite the behavior of the Asm libraries not being syntactically expressible in Rec itself. We also verify an optimizing multi-pass compiler from Rec to Asm, showing that it is compatible with these Asm libraries.}, author = {Sammler, Michael Joachim and Spies, Simon and Song, Youngju and D'Osualdo, Emanuele and Krebbers, Robbert and Garg, Deepak and Dreyer, Derek}, issn = {2475-1421}, journal = {Proceedings of the ACM on Programming Languages}, number = {POPL}, pages = {775--805}, publisher = {Association for Computing Machinery}, title = {{DimSum: A decentralized approach to multi-language semantics and verification}}, doi = {10.1145/3571220}, volume = {7}, year = {2023}, } @article{17507, abstract = {Stellar-mass black holes (BHs) are predicted to be embedded in the disks of active galactic nuclei (AGNs) due to gravitational drag and in situ star formation. However, clear evidence for AGN disk-embedded BHs is currently lacking. Here, as possible electromagnetic signatures of these BHs, we investigate breakout emission from shocks emerging around Blandford–Znajek jets launched from accreting BHs in AGN disks. We assume that most of the highly super-Eddington flow reaches the BH and produces a strong jet, and the jet produces feedback that shuts off accretion and thus leads to episodic flaring. These assumptions, while poorly understood at present, yield observable consequences that can probe the presence of AGN-embedded BHs as well as the accretion process itself. They predict a breakout emission characterized by luminous thermal emission in the X-ray bands and bright broadband nonthermal emission from the infrared to the gamma-ray bands. The flare duration depends on the BH's distance r from the central supermassive BH, varying between 103–106 s for r ∼ 0.01–1 pc. This emission can be discovered by current and future infrared, optical, and X-ray wide-field surveys and monitoring campaigns of nearby AGNs.}, author = {Tagawa, Hiromichi and Kimura, Shigeo S. and Haiman, Zoltán and Perna, Rosalba and Bartos, Imre}, issn = {2041-8205}, journal = {The Astrophysical Journal Letters}, number = {1}, publisher = {American Astronomical Society}, title = {{Observable signatures of stellar-mass black holes in active galactic nuclei}}, doi = {10.3847/2041-8213/acc103}, volume = {946}, year = {2023}, } @article{17513, abstract = {The astrophysical origin of over 90 compact binary mergers discovered by the LIGO and Virgo gravitational wave observatories is an open question. While the unusual mass and spin of some of the discovered objects constrain progenitor scenarios, the observed mergers are consistent with multiple interpretations. A promising approach to solve this question is to consider the observed distributions of binary properties and compare them to expectations from different origin scenarios. Here we describe a new hierarchical population analysis framework to assess the relative contribution of different formation channels simultaneously. For this study we considered binary formation in active galactic nucleus (AGN) disks along with phenomenological models, but the same framework can be extended to other models. We find that high-mass and high-mass-ratio binaries appear more likely to have an AGN origin compared to having the same origin as lower-mass events. Future observations of high-mass black hole mergers could further disentangle the AGN component from other channels.}, author = {Gayathri, V. and Wysocki, Daniel and Yang, Y. and Delfavero, Vera and O’Shaughnessy, R. and Haiman, Zoltán and Tagawa, H. and Bartos, I.}, issn = {2041-8205}, journal = {The Astrophysical Journal Letters}, number = {2}, publisher = {American Astronomical Society}, title = {{Gravitational wave source populations: Disentangling an AGN component}}, doi = {10.3847/2041-8213/acbfb8}, volume = {945}, year = {2023}, } @article{17514, abstract = {Extreme mass-ratio inspirals (EMRIs) take place when a stellar-mass black hole (BH) merges with a supermassive BH (SMBH). The gravitational-wave emission from such an event is expected to be detectable by the future Laser Interferometer Space Antenna (LISA) and other millihertz detectors. It was recently suggested that the EMRI rate in SMBH binary systems is orders of magnitude higher than the EMRI rate around a single SMBH with the same total mass. Here we show that this high rate can produce thousands of SMBH–BH sources at a redshift of unity. We predict that LISA may detect a few hundred of these EMRIs with signal-to-noise ratio above S/N ≥8 within a 4 yr mission lifetime. The remaining subthreshold sources will contribute to a large confusion noise, which is approximately an order of magnitude above LISA’s sensitivity level. Finally, we suggest that the individually detectable systems, as well as the background noise from the subthreshold EMRIs, can be used to constrain the SMBH binary fraction in the low-redshift Universe.}, author = {Naoz, Smadar and Haiman, Zoltán}, issn = {2041-8205}, journal = {The Astrophysical Journal Letters}, number = {2}, publisher = {American Astronomical Society}, title = {{The enhanced population of extreme mass-ratio inspirals in the LISA band from supermassive black hole binaries}}, doi = {10.3847/2041-8213/acf8c9}, volume = {955}, year = {2023}, } @article{17521, abstract = {The upcoming Laser Interferometer Space Antenna (LISA) is expected to detect gravitational waves (GWs) from massive black hole binaries (MBHB). Finding the electromagnetic (EM) counterparts for these GW events will be crucial for understanding how and where MBHBs merge, measuring their redshifts, constraining the Hubble constant and the graviton mass, and for other novel science applications. However, due to poor GW sky localization, multiwavelength, time-dependent EM models are needed to identify the right host galaxy. We studied merging MBHBs embedded in a circumbinary disc (CBD) using high-resolution two-dimensional simulations, with a Γ-law equation of state, incorporating viscous heating, shock heating, and radiative cooling. We simulate the binary from large separation until after merger, allowing us to model the decoupling of the binary from the CBD. We compute the EM signatures and identify distinct features before, during, and after the merger. Our main result is a multiband EM signature: we find that the MBHB produces strong thermal X-ray emission until 1–2 d prior to the merger. However, as the binary decouples from the CBD, the X-ray-bright minidiscs rapidly shrink in size, become disrupted, and the accretion rate drops precipitously. As a result, the thermal X-ray luminosity drops by orders of magnitude, and the source remains X-ray dark for several days, regardless of any post-merger effects such as GW recoil or mass-loss. Looking for the abrupt spectral change where the thermal X-ray disappears is a tell-tale EM signature of LISA mergers that does not require extensive pre-merger monitoring.}, author = {Krauth, Luke Major and Davelaar, Jordy and Westernacher-Schneider, John Ryan and Haiman, Zoltán and Zrake, Jonathan and MacFadyen, Andrew}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {4}, pages = {5441--5454}, publisher = {Oxford University Press}, title = {{Disappearing thermal X-ray emission as a tell-tale signature of merging massive black hole binaries}}, doi = {10.1093/mnras/stad3095}, volume = {526}, year = {2023}, } @article{17522, abstract = {The early growth of black holes (BHs) in high-redshift galaxies is likely feedback regulated. While radiative feedback has been extensively studied, the role of mechanical feedback has received less scrutiny to date. Here, we use high-resolution parsec-scale hydrodynamical simulations to study jet propagation and its effect on 100 M⊙ BH accretion in the dense, low-metallicity gas expected in early protogalaxies. As the jet propagates, it shocks the surrounding gas forming a jet cocoon. The cocoon consists of a rapidly cooling cold phase at the interface with the background gas and an overpressured subsonic phase of reverse shock-heated gas filling the interior. We vary the background gas density and temperature, BH feedback efficiency, and the jet model. We found that the width of the jet cocoon roughly follows a scaling derived by assuming momentum conservation in the jet-propagation direction and energy conservation in the lateral directions. Depending on the assumed gas and jet properties, the cocoon either stays elongated to large radii or isotropizes before reaching the Bondi radius, forming a nearly spherical bubble. Lower jet velocities and higher background gas densities result in self-regulation to higher momentum fluxes and elongated cocoons. In all cases, the outward cocoon momentum flux balances the inward inflowing gas momentum flux near the Bondi radius, which ultimately regulates BH accretion. The time-averaged accretion rate always remains below the Bondi rate, and exceeds the Eddington rate only if the ambient medium is dense and cold, and/or the jet is weak (low velocity and mass loading).}, author = {Su, Kung-Yi and Bryan, Greg L and Haiman, Zoltán and Somerville, Rachel S and Hayward, Christopher C and Faucher-Giguère, Claude-André}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {3}, pages = {4258--4275}, publisher = {Oxford University Press}, title = {{Self-regulation of black hole accretion via jets in early protogalaxies}}, doi = {10.1093/mnras/stad252}, volume = {520}, year = {2023}, } @article{17527, abstract = {The origin of the recently discovered new class of transients, X-ray quasi-periodic eruptions (QPEs), remains a puzzle. Due to their periodicity and association with active galactic nuclei (AGNs), it is natural to relate these eruptions to stars or compact objects in tight orbits around supermassive black holes (SMBHs). In this paper, we predict the properties of emission from bow shocks produced by stars crossing AGN discs, and compare them to the observed properties of QPEs. We find that when a star’s orbit is retrograde and has a low inclination (≲40°) with respect to the AGN disc and the star is massive (≳10 M⊙), the breakout emission from the bow shock can explain the observed duration (∼hours) and X-ray luminosity (∼few × 1042 erg s−1) of QPEs. This model can further explain various observed features of QPEs, such as their complex luminosity evolution, the gradual decline of luminosity of the flares over several years, the evolution of the hardness ratio, the modulation of the luminosity during quiescent phases, and the preference of the central SMBHs to have low masses.}, author = {Tagawa, Hiromichi and Haiman, Zoltán}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {1}, pages = {69--79}, publisher = {Oxford University Press}, title = {{Flares from stars crossing active galactic nucleus discs on low-inclination orbits}}, doi = {10.1093/mnras/stad2616}, volume = {526}, year = {2023}, } @article{17539, abstract = {In this paper, we study how gaseous dynamical friction (DF) affects the motion of fly-by stellar-mass black holes (sBHs) embedded in active galactic nucleus (AGN) discs. We perform three-body integrations of the interaction of two co-planar sBHs in nearby, initially circular orbits around the supermassive black hole. We find that DF can facilitate the formation of gravitationally bound near-Keplerian binaries in AGN discs, and we delineate the discrete ranges of impact parameters and AGN disc parameters for which such captures occur. We also report trends in the bound binaries’ eccentricity and sense of rotation (prograde or retrograde with respect to the background AGN disc) as a function of the impact parameter of the initial encounter. While based on an approximate description of gaseous friction, our results suggest that binary formation in AGN discs should be common and may produce both prograde and retrograde, as well as both circular and eccentric binaries.}, author = {DeLaurentiis, Stanislav and Epstein-Martin, Marguerite and Haiman, Zoltán}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {1}, pages = {1126--1139}, publisher = {Oxford University Press}, title = {{Gas dynamical friction as a binary formation mechanism in AGN discs}}, doi = {10.1093/mnras/stad1412}, volume = {523}, year = {2023}, } @article{17548, abstract = {The shrinking of a binary orbit driven by the interaction with a gaseous circumbinary disc, initially advocated as a potential way to catalyse the binary merger, has recently been debated in the case of geometrically thick (i.e. with H/R ≳ 0.1) discs. However, a clear consensus is still missing mainly owing to numerical limitations, such as fixed orbit binaries or lack of resolution inside the cavity carved by the binary in its circumbinary disc. In this work, we assess the importance of evolving the binary orbit by means of hydrodynamic simulations performed with the code gizmo in meshless finite mass mode. In order to model the interaction between equal mass circular binaries and their locally isothermal circumbinary discs, we enforce hyper-Lagrangian resolution inside the cavity. We find that fixing the binary orbit ultimately leads to an overestimate of the gravitational torque that the gas exerts on the binary and an underestimate of the torque due to the accretion of material on to the binary components. Furthermore, we find that the modulation of the accretion rate on the binary orbital period is strongly suppressed in the fixed orbit simulation, while it is clearly present in the live binary simulations. This has potential implications for the prediction of the observable periodicities in massive black hole binary candidates.}, author = {Franchini, Alessia and Lupi, Alessandro and Sesana, Alberto and Haiman, Zoltán}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {1}, pages = {1569--1574}, publisher = {Oxford University Press}, title = {{The importance of live binary evolution in numerical simulations of binaries embedded in circumbinary discs}}, doi = {10.1093/mnras/stad1070}, volume = {522}, year = {2023}, } @article{17549, abstract = {Studies of rest-frame optical emission in quasars at z>6 have historically been limited by the wavelengths accessible by ground-based telescopes. The James Webb Space Telescope (JWST) now offers the opportunity to probe this emission deep into the reionization epoch. We report the observations of eight quasars at z>6.5 using the JWST/NIRCam Wide Field Slitless Spectroscopy, as a part of the ''A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE)" program. Our JWST spectra cover the quasars' emission between rest frame ∼ 4100 and 5100 Å. The profiles of these quasars' broad Hβ emission lines span a FWHM from 3000 to 6000 km s−1. The Hβ-based virial black hole (BH) masses, ranging from 0.6 to 2.1 billion solar masses, are generally consistent with their MgII-based BH masses. The new measurements based on the more reliable Hβ tracer thus confirm the existence of billion solar-mass BHs in the reionization epoch. In the observed [OIII] λλ4960,5008 doublets of these luminous quasars, broad components are more common than narrow core components (≤ 1200 km s−1), and only one quasar shows stronger narrow components than broad. Two quasars exhibit significantly broad and blueshifted [OIII] emission, thought to trace galactic-scale outflows, with median velocities of −610 km s−1 and −1430 km s−1 relative to the [CII] 158μm line. All eight quasars show strong optical FeII emission, and follow the Eigenvector 1 relations defined by low-redshift quasars. The entire ASPIRE program will eventually cover 25 quasars and provide a statistical sample for the studies of the BHs and quasar spectral properties.}, author = {Yang, Jinyi and Wang, Feige and Fan, Xiaohui and Hennawi, Joseph F. and Barth, Aaron J. and Bañados, Eduardo and Sun, Fengwu and Liu, Weizhe and Cai, Zheng and Jiang, Linhua and Li, Zihao and Onoue, Masafusa and Schindler, Jan-Torge and Shen, Yue and Wu, Yunjing and Bhowmick, Aklant K. and Bieri, Rebekka and Blecha, Laura and Bosman, Sarah and Champagne, Jaclyn B. and Colina, Luis and Connor, Thomas and Costa, Tiago and Davies, Frederick B. and Decarli, Roberto and De Rosa, Gisella and Drake, Alyssa B. and Egami, Eiichi and Eilers, Anna-Christina and Evans, Analis E. and Farina, Emanuele Paolo and Habouzit, Melanie and Haiman, Zoltán and Jin, Xiangyu and Jun, Hyunsung D. and Kakiichi, Koki and Khusanova, Yana and Kulkarni, Girish and Loiacono, Federica and Lupi, Alessandro and Mazzucchelli, Chiara and Pan, Zhiwei and Rojas-Ruiz, Sofía and Strauss, Michael A. and Tee, Wei Leong and Trakhtenbrot, Benny and Trebitsch, Maxime and Venemans, Bram and Vestergaard, Marianne and Volonteri, Marta and Walter, Fabian and Xie, Zhang-Liang and Yue, Minghao and Zhang, Haowen and Zhang, Huanian and Zou, Siwei}, issn = {2041-8205}, journal = {The Astrophysical Journal Letters}, number = {1}, publisher = {American Astronomical Society}, title = {{A SPectroscopic survey of biased halos in the reionization Era (ASPIRE): A first look at the rest-frame optical spectra of > 6.5 quasars using JWST}}, doi = {10.3847/2041-8213/acc9c8}, volume = {951}, year = {2023}, } @article{17551, abstract = {We present cosmological constraints from the Subaru Hyper Suprime-Cam (HSC) first-year weak lensing shear catalogue using convolutional neural networks (CNNs) and conventional summary statistics. We crop 19 3×3deg2 sub-fields from the first-year area, divide the galaxies with redshift 0.3≤z≤1.5 into four equally-spaced redshift bins, and perform tomographic analyses. We develop a pipeline to generate simulated convergence maps from cosmological N-body simulations, where we account for effects such as intrinsic alignments (IAs), baryons, photometric redshift errors, and point spread function errors, to match characteristics of the real catalogue. We train CNNs that can predict the underlying parameters from the simulated maps, and we use them to construct likelihood functions for Bayesian analyses. In the Λ cold dark matter model with two free cosmological parameters Ωm and σ8, we find Ωm=0.278+0.037−0.035, S8≡(Ωm/0.3)0.5σ8=0.793+0.017−0.018, and the IA amplitude AIA=0.20+0.55−0.58. In a model with four additional free baryonic parameters, we find Ωm=0.268+0.040−0.036, S8=0.819+0.034−0.024, and AIA=−0.16+0.59−0.58, with the baryonic parameters not being well-constrained. We also find that statistical uncertainties of the parameters by the CNNs are smaller than those from the power spectrum (5--24 percent smaller for S8 and a factor of 2.5--3.0 smaller for Ωm), showing the effectiveness of CNNs for uncovering additional cosmological information from the HSC data. With baryons, the S8 discrepancy between HSC first-year data and Planck 2018 is reduced from ∼2.2σ to 0.3--0.5σ.}, author = {Lu, Tianhuan and Haiman, Zoltán and Li, Xiangchong}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {2}, pages = {2050--2066}, publisher = {Oxford University Press}, title = {{Cosmological constraints from HSC survey first-year data using deep learning}}, doi = {10.1093/mnras/stad686}, volume = {521}, year = {2023}, }