@article{15063,
  abstract     = {We consider the least singular value of a large random matrix with real or complex i.i.d. Gaussian entries shifted by a constant z∈C. We prove an optimal lower tail estimate on this singular value in the critical regime where z is around the spectral edge, thus improving the classical bound of Sankar, Spielman and Teng (SIAM J. Matrix Anal. Appl. 28:2 (2006), 446–476) for the particular shift-perturbation in the edge regime. Lacking Brézin–Hikami formulas in the real case, we rely on the superbosonization formula (Comm. Math. Phys. 283:2 (2008), 343–395).},
  author       = {Cipolloni, Giorgio and Erdös, László and Schröder, Dominik J},
  issn         = {2690-1005},
  journal      = {Probability and Mathematical Physics},
  keywords     = {General Medicine},
  number       = {1},
  pages        = {101--146},
  publisher    = {Mathematical Sciences Publishers},
  title        = {{Optimal lower bound on the least singular value of the shifted Ginibre ensemble}},
  doi          = {10.2140/pmp.2020.1.101},
  volume       = {1},
  year         = {2020},
}

@article{15064,
  abstract     = {We call a continuous self-map that reveals itself through a discrete set of point-value pairs a sampled dynamical system. Capturing the available information with chain maps on Delaunay complexes, we use persistent homology to quantify the evidence of recurrent behavior. We establish a sampling theorem to recover the eigenspaces of the endomorphism on homology induced by the self-map. Using a combinatorial gradient flow arising from the discrete Morse theory for Čech and Delaunay complexes, we construct a chain map to transform the problem from the natural but expensive Čech complexes to the computationally efficient Delaunay triangulations. The fast chain map algorithm has applications beyond dynamical systems.},
  author       = {Bauer, U. and Edelsbrunner, Herbert and Jablonski, Grzegorz and Mrozek, M.},
  issn         = {2367-1734},
  journal      = {Journal of Applied and Computational Topology},
  number       = {4},
  pages        = {455--480},
  publisher    = {Springer Nature},
  title        = {{Čech-Delaunay gradient flow and homology inference for self-maps}},
  doi          = {10.1007/s41468-020-00058-8},
  volume       = {4},
  year         = {2020},
}

@inproceedings{15074,
  abstract     = {We introduce a new graph problem, the token dropping game, and we show how to solve it efficiently in a distributed setting. We use the token dropping game as a tool to design an efficient distributed algorithm for the stable orientation problem, which is a special case of the more general locally optimal semi-matching problem. The prior work by Czygrinow et al. (DISC 2012) finds a locally optimal semi-matching in O(Δ⁵) rounds in graphs of maximum degree Δ, which directly implies an algorithm with the same runtime for stable orientations. We improve the runtime to O(Δ⁴) for stable orientations and prove a lower bound of Ω(Δ) rounds.},
  author       = {Brandt, Sebastian and Keller, Barbara and Rybicki, Joel and Suomela, Jukka and Uitto, Jara},
  booktitle    = {34th International Symposium on Distributed Computing},
  location     = {Virtual},
  publisher    = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
  title        = {{Brief announcement: Efficient load-balancing through distributed token dropping}},
  doi          = {10.4230/LIPIcs.DISC.2020.40},
  volume       = {179},
  year         = {2020},
}

@inproceedings{15077,
  abstract     = {We consider the following dynamic load-balancing process: given an underlying graph G with n nodes, in each step t≥ 0, one unit of load is created, and placed at a randomly chosen graph node. In the same step, the chosen node picks a random neighbor, and the two nodes balance their loads by averaging them. We are interested in the expected gap between the minimum and maximum loads at nodes as the process progresses, and its dependence on n and on the graph structure. Variants of the above graphical balanced allocation process have been studied previously by Peres, Talwar, and Wieder [Peres et al., 2015], and by Sauerwald and Sun [Sauerwald and Sun, 2015]. These authors left as open the question of characterizing the gap in the case of cycle graphs in the dynamic case, where weights are created during the algorithm’s execution. For this case, the only known upper bound is of 𝒪(n log n), following from a majorization argument due to [Peres et al., 2015], which analyzes a related graphical allocation process. In this paper, we provide an upper bound of 𝒪 (√n log n) on the expected gap of the above process for cycles of length n. We introduce a new potential analysis technique, which enables us to bound the difference in load between k-hop neighbors on the cycle, for any k ≤ n/2. We complement this with a "gap covering" argument, which bounds the maximum value of the gap by bounding its value across all possible subsets of a certain structure, and recursively bounding the gaps within each subset. We provide analytical and experimental evidence that our upper bound on the gap is tight up to a logarithmic factor.},
  author       = {Alistarh, Dan-Adrian and Nadiradze, Giorgi and Sabour, Amirmojtaba},
  booktitle    = {47th International Colloquium on Automata, Languages, and Programming},
  location     = {Saarbrücken, Germany, Virtual},
  publisher    = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
  title        = {{Dynamic averaging load balancing on cycles}},
  doi          = {10.4230/LIPIcs.ICALP.2020.7},
  volume       = {168},
  year         = {2020},
}

@inproceedings{15082,
  abstract     = {Two plane drawings of geometric graphs on the same set of points are called disjoint compatible if their union is plane and they do not have an edge in common. For a given set S of 2n points two plane drawings of perfect matchings M1 and M2 (which do not need to be disjoint nor compatible) are disjoint tree-compatible if there exists a plane drawing of a spanning tree T on S which is disjoint compatible to both M1 and M2.
We show that the graph of all disjoint tree-compatible perfect geometric matchings on 2n points in convex position is connected if and only if 2n ≥ 10. Moreover, in that case the diameter
of this graph is either 4 or 5, independent of n.},
  author       = {Aichholzer, Oswin and Obmann, Julia and Patak, Pavel and Perz, Daniel and Tkadlec, Josef},
  booktitle    = {36th European Workshop on Computational Geometry},
  location     = {Würzburg, Germany, Virtual},
  title        = {{Disjoint tree-compatible plane perfect matchings}},
  year         = {2020},
}

@misc{13056,
  abstract     = {This datasets comprises all data shown in plots of the submitted article "Converting microwave and telecom photons with a silicon photonic nanomechanical interface". Additional raw data are available from the corresponding author on reasonable request.},
  author       = {Arnold, Georg M and Wulf, Matthias and Barzanjeh, Shabir and Redchenko, Elena and Rueda Sanchez, Alfredo R and Hease, William J and Hassani, Farid and Fink, Johannes M},
  publisher    = {Zenodo},
  title        = {{Converting microwave and telecom photons with a silicon photonic nanomechanical interface}},
  doi          = {10.5281/ZENODO.3961561},
  year         = {2020},
}

@misc{13060,
  abstract     = {Coinfections with multiple pathogens can result in complex within-host dynamics affecting virulence and transmission. Whilst multiple infections are intensively studied in solitary hosts, it is so far unresolved how social host interactions interfere with pathogen competition, and if this depends on coinfection diversity. We studied how the collective disease defenses of ants – their social immunity ­– influence pathogen competition in coinfections of same or different fungal pathogen species. Social immunity reduced virulence for all pathogen combinations, but interfered with spore production only in different-species coinfections. Here, it decreased overall pathogen sporulation success, whilst simultaneously increasing co-sporulation on individual cadavers and maintaining a higher pathogen diversity at the community-level. Mathematical modeling revealed that host sanitary care alone can modulate competitive outcomes between pathogens, giving advantage to fast-germinating, thus less grooming-sensitive ones. Host social interactions can hence modulate infection dynamics in coinfected group members, thereby altering pathogen communities at the host- and population-level.},
  author       = {Milutinovic, Barbara and Stock, Miriam and Grasse, Anna V and Naderlinger, Elisabeth and Hilbe, Christian and Cremer, Sylvia},
  publisher    = {Dryad},
  title        = {{Social immunity modulates competition between coinfecting pathogens}},
  doi          = {10.5061/DRYAD.CRJDFN318},
  year         = {2020},
}

@misc{13065,
  abstract     = {Domestication is a human-induced selection process that imprints the genomes of domesticated populations over a short evolutionary time scale, and that occurs in a given demographic context. Reconstructing historical gene flow, effective population size changes and their timing is therefore of fundamental interest to understand how plant demography and human selection jointly shape genomic divergence during domestication. Yet, the comparison under a single statistical framework of independent domestication histories across different crop species has been little evaluated so far. Thus, it is unclear whether domestication leads to convergent demographic changes that similarly affect crop genomes. To address this question, we used existing and new transcriptome data on three crop species of Solanaceae (eggplant, pepper and tomato), together with their close wild relatives. We fitted twelve demographic models of increasing complexity on the unfolded joint allele frequency spectrum for each wild/crop pair, and we found evidence for both shared and species-specific demographic processes between species. A convergent history of domestication with gene-flow was inferred for all three species, along with evidence of strong reduction in the effective population size during the cultivation stage of tomato and pepper. The absence of any reduction in size of the crop in eggplant stands out from the classical view of the domestication process; as does the existence of a “protracted period” of management before cultivation. Our results also suggest divergent management strategies of modern cultivars among species as their current demography substantially differs. Finally, the timing of domestication is species-specific and supported by the few historical records available.},
  author       = {Arnoux, Stephanie and Fraisse, Christelle and Sauvage, Christopher},
  publisher    = {Dryad},
  title        = {{VCF files of synonymous SNPs related to: Genomic inference of complex domestication histories in three Solanaceae species}},
  doi          = {10.5061/DRYAD.Q2BVQ83HD},
  year         = {2020},
}

@misc{13070,
  abstract     = {This dataset comprises all data shown in the figures of the submitted article "Surpassing the resistance quantum with a geometric superinductor". Additional raw data are available from the corresponding author on reasonable request.},
  author       = {Peruzzo, Matilda and Trioni, Andrea and Hassani, Farid and Zemlicka, Martin and Fink, Johannes M},
  publisher    = {Zenodo},
  title        = {{Surpassing the resistance quantum with a geometric superinductor}},
  doi          = {10.5281/ZENODO.4052882},
  year         = {2020},
}

@misc{13071,
  abstract     = {This dataset comprises all data shown in the plots of the main part of the submitted article "Bidirectional Electro-Optic Wavelength Conversion in the Quantum Ground State". Additional raw data are available from the corresponding author on reasonable request.},
  author       = {Hease, William J and Rueda Sanchez, Alfredo R and Sahu, Rishabh and Wulf, Matthias and Arnold, Georg M and Schwefel, Harald and Fink, Johannes M},
  publisher    = {Zenodo},
  title        = {{Bidirectional electro-optic wavelength conversion in the quantum ground state}},
  doi          = {10.5281/ZENODO.4266025},
  year         = {2020},
}

@misc{13073,
  abstract     = {The Mytilus complex of marine mussel species forms a mosaic of hybrid zones, found across temperate regions of the globe. This allows us to study "replicated" instances of secondary contact between closely-related species. Previous work on this complex has shown that local introgression is both widespread and highly heterogeneous, and has identified SNPs that are outliers of differentiation between lineages. Here, we developed an ancestry-informative panel of such SNPs. We then compared their frequencies in newly-sampled populations, including samples from within the hybrid zones, and parental populations at different distances from the contact. Results show that close to the hybrid zones, some outlier loci are near to fixation for the heterospecific allele, suggesting enhanced local introgression, or the local sweep of a shared ancestral allele. Conversely, genomic cline analyses, treating local parental populations as the reference, reveal a globally high concordance among loci, albeit with a few signals of asymmetric introgression. Enhanced local introgression at specific loci is consistent with the early transfer of adaptive variants after contact, possibly including asymmetric bi-stable variants (Dobzhansky-Muller incompatibilities), or haplotypes loaded with fewer deleterious mutations. Having escaped one barrier, however, these variants can be trapped or delayed at the next barrier, confining the introgression locally. These results shed light on the decay of species barriers during phases of contact.},
  author       = {Simon, Alexis and Fraisse, Christelle and El Ayari, Tahani and Liautard-Haag, Cathy and Strelkov, Petr and Welch, John and Bierne, Nicolas},
  publisher    = {Dryad},
  title        = {{How do species barriers decay? concordance and local introgression in mosaic hybrid zones of mussels}},
  doi          = {10.5061/DRYAD.R4XGXD29N},
  year         = {2020},
}

@article{13341,
  abstract     = {Scanning nanoscale superconducting quantum interference devices (nanoSQUIDs)
are of growing interest for highly sensitive quantitative imaging of magnetic,
spintronic, and transport properties of low-dimensional systems. Utilizing
specifically designed grooved quartz capillaries pulled into a sharp pipette,
we have fabricated the smallest SQUID-on-tip (SOT) devices with effective
diameters down to 39 nm. Integration of a resistive shunt in close proximity to
the pipette apex combined with self-aligned deposition of In and Sn, have
resulted in SOT with a flux noise of 42 n$\Phi_0$Hz$^{-1/2}$, yielding a record
low spin noise of 0.29 $\mu_B$Hz$^{-1/2}$. In addition, the new SOTs function
at sub-Kelvin temperatures and in high magnetic fields of over 2.5 T.
Integrating the SOTs into a scanning probe microscope allowed us to image the
stray field of a single Fe$_3$O$_4$ nanocube at 300 mK. Our results show that
the easy magnetization axis direction undergoes a transition from the (111)
direction at room temperature to an in-plane orientation, which could be
attributed to the Verwey phase transition in Fe$_3$O$_4$.},
  author       = {Anahory, Y. and Naren, H. R. and Lachman, E. O. and Sinai, S. Buhbut and Uri, A. and Embon, L. and Yaakobi, E. and Myasoedov, Y. and Huber, M. E. and Klajn, Rafal and Zeldov, E.},
  issn         = {2040-3372},
  journal      = {Nanoscale},
  number       = {5},
  pages        = {3174--3182},
  publisher    = {Royal Society of Chemistry},
  title        = {{SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging}},
  doi          = {10.1039/C9NR08578E},
  volume       = {12},
  year         = {2020},
}

@article{13361,
  abstract     = {In nature, light is harvested by photoactive proteins to drive a range of biological processes, including photosynthesis, phototaxis, vision, and ultimately life. Bacteriorhodopsin, for example, is a protein embedded within archaeal cell membranes that binds the chromophore retinal within its hydrophobic pocket. Exposure to light triggers regioselective photoisomerization of the confined retinal, which in turn initiates a cascade of conformational changes within the protein, triggering proton flux against the concentration gradient, providing the microorganisms with the energy to live. We are inspired by these functions in nature to harness light energy using synthetic photoswitches under confinement. Like retinal, synthetic photoswitches require some degree of conformational flexibility to isomerize. In nature, the conformational change associated with retinal isomerization is accommodated by the structural flexibility of the opsin host, yet it results in steric communication between the chromophore and the protein. Similarly, we strive to design systems wherein isomerization of confined photoswitches results in steric communication between a photoswitch and its confining environment. To achieve this aim, a balance must be struck between molecular crowding and conformational freedom under confinement: too much crowding prevents switching, whereas too much freedom resembles switching of isolated molecules in solution, preventing communication.

In this Account, we discuss five classes of synthetic light-switchable compounds—diarylethenes, anthracenes, azobenzenes, spiropyrans, and donor–acceptor Stenhouse adducts—comparing their behaviors under confinement and in solution. The environments employed to confine these photoswitches are diverse, ranging from planar surfaces to nanosized cavities within coordination cages, nanoporous frameworks, and nanoparticle aggregates. The trends that emerge are primarily dependent on the nature of the photoswitch and not on the material used for confinement. In general, we find that photoswitches requiring less conformational freedom for switching are, as expected, more straightforward to isomerize reversibly under confinement. Because these compounds undergo only small structural changes upon isomerization, however, switching does not propagate into communication with their environment. Conversely, photoswitches that require more conformational freedom are more challenging to switch under confinement but also can influence system-wide behavior.

Although we are primarily interested in the effects of geometric constraints on photoswitching under confinement, additional effects inevitably emerge when a compound is removed from solution and placed within a new, more crowded environment. For instance, we have found that compounds that convert to zwitterionic isomers upon light irradiation often experience stabilization of these forms under confinement. This effect results from the mutual stabilization of zwitterions that are brought into close proximity on surfaces or within cavities. Furthermore, photoswitches can experience preorganization under confinement, influencing the selectivity and efficiency of their photoreactions. Because intermolecular interactions arising from confinement cannot be considered independently from the effects of geometric constraints, we describe all confinement effects concurrently throughout this Account.},
  author       = {Grommet, Angela B. and Lee, Lucia M. and Klajn, Rafal},
  issn         = {1520-4898},
  journal      = {Accounts of Chemical Research},
  keywords     = {General Medicine, General Chemistry},
  number       = {11},
  pages        = {2600--2610},
  publisher    = {American Chemical Society},
  title        = {{Molecular photoswitching in confined spaces}},
  doi          = {10.1021/acs.accounts.0c00434},
  volume       = {53},
  year         = {2020},
}

@article{13362,
  abstract     = {Aggregation of organic molecules can drastically affect their physicochemical properties. For instance, the optical properties of BODIPY dyes are inherently related to the degree of aggregation and the mutual orientation of BODIPY units within these aggregates. Whereas the noncovalent aggregation of various BODIPY dyes has been studied in diverse media, the ill-defined nature of these aggregates has made it difficult to elucidate the structure–property relationships. Here, we studied the encapsulation of three structurally simple BODIPY derivatives within the hydrophobic cavity of a water-soluble, flexible PdII6L4 coordination cage. The cavity size allowed for the selective encapsulation of two dye molecules, irrespective of the substitution pattern on the BODIPY core. Working with a model, a pentamethyl-substituted derivative, we found that the mutual orientation of two BODIPY units in the cage’s cavity was remarkably similar to that in the crystalline state of the free dye, allowing us to isolate and characterize the smallest possible noncovalent H-type BODIPY aggregate, namely, an H-dimer. Interestingly, a CF3-substituted BODIPY, known for forming J-type aggregates, was also encapsulated as an H-dimer. Taking advantage of the dynamic nature of encapsulation, we developed a system in which reversible switching between H- and J-aggregates can be induced for multiple cycles simply by addition and subsequent destruction of the cage. We expect that the ability to rapidly and reversibly manipulate the optical properties of supramolecular inclusion complexes in aqueous media will open up avenues for developing detection systems that operate within biological environments.},
  author       = {Gemen, Julius and Ahrens, Johannes and Shimon, Linda J. W. and Klajn, Rafal},
  issn         = {1520-5126},
  journal      = {Journal of the American Chemical Society},
  keywords     = {Colloid and Surface Chemistry, Biochemistry, General Chemistry, Catalysis},
  number       = {41},
  pages        = {17721--17729},
  publisher    = {American Chemical Society},
  title        = {{Modulating the optical properties of BODIPY dyes by noncovalent dimerization within a flexible coordination cage}},
  doi          = {10.1021/jacs.0c08589},
  volume       = {142},
  year         = {2020},
}

@article{13363,
  abstract     = {Temporal activation of biological processes by visible light and subsequent return to an inactive state in the absence of light is an essential characteristic of photoreceptor cells. Inspired by these phenomena, light-responsive materials are very attractive due to the high spatiotemporal control of light irradiation, with light being able to precisely orchestrate processes repeatedly over many cycles. Herein, it is reported that light-driven proton transfer triggered by a merocyanine-based photoacid can be used to modulate the permeability of pH-responsive polymersomes through cyclic, temporally controlled protonation and deprotonation of the polymersome membrane. The membranes can undergo repeated light-driven swelling–contraction cycles without losing functional effectiveness. When applied to enzyme loaded-nanoreactors, this membrane responsiveness is used for the reversible control of enzymatic reactions. This combination of the merocyanine-based photoacid and pH-switchable nanoreactors results in rapidly responding and versatile supramolecular systems successfully used to switch enzymatic reactions ON and OFF on demand.},
  author       = {Moreno, Silvia and Sharan, Priyanka and Engelke, Johanna and Gumz, Hannes and Boye, Susanne and Oertel, Ulrich and Wang, Peng and Banerjee, Susanta and Klajn, Rafal and Voit, Brigitte and Lederer, Albena and Appelhans, Dietmar},
  issn         = {1613-6829},
  journal      = {Small},
  keywords     = {Biomaterials, Biotechnology, General Materials Science, General Chemistry},
  number       = {37},
  publisher    = {Wiley},
  title        = {{Light‐driven proton transfer for cyclic and temporal switching of enzymatic nanoreactors}},
  doi          = {10.1002/smll.202002135},
  volume       = {16},
  year         = {2020},
}

@article{13364,
  abstract     = {Photochromic molecules undergo reversible isomerization upon irradiation with light at different wavelengths, a process that can alter their physical and chemical properties. For instance, dihydropyrene (DHP) is a deep-colored compound that isomerizes to light-brown cyclophanediene (CPD) upon irradiation with visible light. CPD can then isomerize back to DHP upon irradiation with UV light or thermally in the dark. Conversion between DHP and CPD is thought to proceed via a biradical intermediate; bimolecular events involving this unstable intermediate thus result in rapid decomposition and poor cycling performance. Here, we show that the reversible isomerization of DHP can be stabilized upon confinement within a PdII6L4 coordination cage. By protecting this reactive intermediate using the cage, each isomerization reaction proceeds to higher yield, which significantly decreases the fatigue experienced by the system upon repeated photocycling. Although molecular confinement is known to help stabilize reactive species, this effect is not typically employed to protect reactive intermediates and thus improve reaction yields. We envisage that performing reactions under confinement will not only improve the cyclic performance of photochromic molecules, but may also increase the amount of product obtainable from traditionally low-yielding organic reactions.},
  author       = {Canton, Martina and Grommet, Angela B. and Pesce, Luca and Gemen, Julius and Li, Shiming and Diskin-Posner, Yael and Credi, Alberto and Pavan, Giovanni M. and Andréasson, Joakim and Klajn, Rafal},
  issn         = {1520-5126},
  journal      = {Journal of the American Chemical Society},
  keywords     = {Colloid and Surface Chemistry, Biochemistry, General Chemistry, Catalysis},
  number       = {34},
  pages        = {14557--14565},
  publisher    = {American Chemical Society},
  title        = {{Improving fatigue resistance of dihydropyrene by encapsulation within a coordination cage}},
  doi          = {10.1021/jacs.0c06146},
  volume       = {142},
  year         = {2020},
}

@article{13365,
  abstract     = {Photoswitchable molecules are employed for many applications, from the development of active materials to the design of stimuli-responsive molecular systems and light-powered molecular machines. To fully exploit their potential, we must learn ways to control the mechanism and kinetics of their photoinduced isomerization. One possible strategy involves confinement of photoresponsive switches such as azobenzenes or spiropyrans within crowded molecular environments, which may allow control over their light-induced conversion. However, the molecular factors that influence and control the switching process under realistic conditions and within dynamic molecular regimes often remain difficult to ascertain. As a case study, here we have employed molecular models to probe the isomerization of azobenzene guests within a Pd(II)-based coordination cage host in water. Atomistic molecular dynamics and metadynamics simulations allow us to characterize the flexibility of the cage in the solvent, the (rare) guest encapsulation and release events, and the relative probability/kinetics of light-induced isomerization of azobenzene analogues in these host–guest systems. In this way, we can reconstruct the mechanism of azobenzene switching inside the cage cavity and explore key molecular factors that may control this event. We obtain a molecular-level insight on the effects of crowding and host–guest interactions on azobenzene isomerization. The detailed picture elucidated by this study may enable the rational design of photoswitchable systems whose reactivity can be controlled via host–guest interactions.},
  author       = {Pesce, Luca and Perego, Claudio and Grommet, Angela B. and Klajn, Rafal and Pavan, Giovanni M.},
  issn         = {1520-5126},
  journal      = {Journal of the American Chemical Society},
  keywords     = {Colloid and Surface Chemistry, Biochemistry, General Chemistry, Catalysis},
  number       = {21},
  pages        = {9792--9802},
  publisher    = {American Chemical Society},
  title        = {{Molecular factors controlling the isomerization of Azobenzenes in the cavity of a flexible coordination cage}},
  doi          = {10.1021/jacs.0c03444},
  volume       = {142},
  year         = {2020},
}

@article{13460,
  abstract     = {Binary interaction can cause stellar envelopes to be stripped, which significantly reduces the radius of the star. The orbit of a binary composed of a stripped star and a compact object can therefore be so tight that the gravitational radiation the system produces reaches frequencies accessible to the Laser Interferometer Space Antenna (LISA). Two such stripped stars in tight orbits with white dwarfs are known so far (ZTF J2130+4420 and CD−30°11223), but many more are expected to exist. These binaries provide important constraints for binary evolution models and may be used as LISA verification sources. We develop a Monte Carlo code that uses detailed evolutionary models to simulate the Galactic population of stripped stars in tight orbits with either neutron star or white dwarf companions. We predict 0–100 stripped star + white dwarf binaries and 0–4 stripped star + neutron star binaries with a signal-to-noise ratio >5 after 10 yr of observations with LISA. More than 90% of these binaries are expected to show large radial velocity shifts of ≳200 $\,\mathrm{km}\,{{\rm{s}}}^{-1}$, which are spectroscopically detectable. Photometric variability due to tidal deformation of the stripped star is also expected and has been observed in ZTF J2130+4420 and CD−30°11223. In addition, the stripped star + neutron star binaries are expected to be X-ray bright with LX ≳ 1033–1036 $\,\mathrm{erg}\,{{\rm{s}}}^{-1}$. Our results show that stripped star binaries are promising multimessenger sources for the upcoming electromagnetic and gravitational wave facilities.},
  author       = {Götberg, Ylva Louise Linsdotter and Korol, V. and Lamberts, A. and Kupfer, T. and Breivik, K. and Ludwig, B. and Drout, M. R.},
  issn         = {1538-4357},
  journal      = {The Astrophysical Journal},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {1},
  publisher    = {American Astronomical Society},
  title        = {{Stars stripped in binaries: The living gravitational-wave sources}},
  doi          = {10.3847/1538-4357/abbda5},
  volume       = {904},
  year         = {2020},
}

@article{13461,
  abstract     = {High-resolution numerical simulations including feedback and aimed at calculating the escape fraction (fesc) of hydrogen-ionizing photons often assume stellar radiation based on single-stellar population synthesis models. However, strong evidence suggests the binary fraction of massive stars is ≳70%. Moreover, simulations so far have yielded values of fesc falling only on the lower end of the ∼10%–20% range, the amount presumed necessary to reionize the universe. Analyzing a high-resolution (4 pc) cosmological radiation-hydrodynamic simulation, we study how fesc changes when we include two different products of binary stellar evolution—stars stripped of their hydrogen envelopes and massive blue stragglers. Both produce significant amounts of ionizing photons 10–200 Myr after each starburst. We find the relative importance of these photons to be amplified with respect to escaped ionizing photons, because peaks in star formation rates (SFRs) and fesc are often out of phase by this 10–200 Myr. Additionally, low-mass, bursty galaxies emit Lyman continuum radiation primarily from binary products when SFRs are low. Observations of these galaxies by the James Webb Space Telescope could provide crucial information on the evolution of binary stars as a function of redshift. Overall, including stripped stars and massive blue stragglers increases our photon-weighted mean escape fraction ($\langle {f}_{\mathrm{esc}}\rangle $) by ∼13% and ∼10%, respectively, resulting in $\langle {f}_{\mathrm{esc}}\rangle =17 \% $. Our results emphasize that using updated stellar population synthesis models with binary stellar evolution provides a more sound physical basis for stellar reionization.},
  author       = {Secunda, Amy and Cen, Renyue and Kimm, Taysun and Götberg, Ylva Louise Linsdotter and de Mink, Selma E.},
  issn         = {1538-4357},
  journal      = {The Astrophysical Journal},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {1},
  publisher    = {American Astronomical Society},
  title        = {{Delayed photons from binary evolution help reionize the universe}},
  doi          = {10.3847/1538-4357/abaefa},
  volume       = {901},
  year         = {2020},
}

@article{13463,
  abstract     = {Present and upcoming time-domain astronomy efforts, in part driven by gravitational-wave follow-up campaigns, will unveil a variety of rare explosive transients in the sky. Here, we focus on pulsational pair-instability evolution, which can result in signatures that are observable with electromagnetic and gravitational waves. We simulated grids of bare helium stars to characterize the resulting black hole (BH) masses together with the ejecta composition, velocity, and thermal state. We find that the stars do not react “elastically” to the thermonuclear ignition in the core: there is not a one-to-one correspondence between pair-instability driven ignition and mass ejections, which causes ambiguity as to what is an observable pulse. In agreement with previous studies, we find that for initial helium core masses of 37.5 M⊙ ≲ MHe, init ≲ 41 M⊙, corresponding to carbon-oxygen core masses 27.5 M⊙ ≲ MCO ≲ 30.1 M⊙, the explosions are not strong enough to affect the surface. With increasing initial helium core mass, they become progressively stronger causing first large radial expansion (41 M⊙ ≲ MHe, init ≲ 42 M⊙, corresponding to 30.1 M⊙ ≲ MCO ≲ 30.8 M⊙) and, finally, also mass ejection episodes (for MHe, init ≳ 42 M⊙, or MCO ≳ 30.8 M⊙). The lowest mass helium core to be fully disrupted in a pair-instability supernova is MHe, init ≃ 80 M⊙, corresponding to MCO ≃ 55 M⊙. Models with MHe, init ≳ 200 M⊙ (MCO ≳ 114 M⊙) reach the photodisintegration regime, resulting in BHs with masses of MBH ≳ 125 M⊙. Although this is currently considered unlikely, if BHs from these models form via (weak) explosions, the previously-ejected material might be hit by the blast wave and convert kinetic energy into observable electromagnetic radiation. We characterize the hydrogen-free circumstellar material from the pulsational pair-instability of helium cores by simply assuming that the ejecta maintain a constant velocity after ejection. We find that our models produce helium-rich ejecta with mass of 10−3 M⊙ ≲ MCSM ≲ 40 M⊙, the larger values corresponding to the more massive progenitor stars. These ejecta are typically launched at a few thousand km s−1 and reach distances of ∼1012 − 1015 cm before the core-collapse of the star. The delays between mass ejection events and the final collapse span a wide and mass-dependent range (from subhour to 104 years), and the shells ejected can also collide with each other, powering supernova impostor events before the final core-collapse. The range of properties we find suggests a possible connection with (some) type Ibn supernovae.},
  author       = {Renzo, M. and Farmer, R. and Justham, S. and Götberg, Ylva Louise Linsdotter and de Mink, S. E. and Zapartas, E. and Marchant, P. and Smith, N.},
  issn         = {1432-0746},
  journal      = {Astronomy & Astrophysics},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  publisher    = {EDP Sciences},
  title        = {{Predictions for the hydrogen-free ejecta of pulsational pair-instability supernovae}},
  doi          = {10.1051/0004-6361/202037710},
  volume       = {640},
  year         = {2020},
}