@inproceedings{15228, abstract = {We describe a new implementation of a broad-band soft X-ray polarimeter, substantially based on a previous design. This implementation, the Pioneer Soft X-ray Polarimeter (PiSoX) is a SmallSat, designed for NASA’s call for Astrophysics Pioneers, small missions that could be CubeSats, balloon experiments, or SmallSats. As in REDSoX, the grating arrangement is designed optimally for the purpose of polarimetry with broad-band focussing optics by matching the dispersion of the spectrometer channels to laterally graded multilayers (LGMLs). The system can achieve polarization modulation factors over 90%. For PiSoX, the optics are lightweight Si mirrors in a one-bounce parabolic configuration. High efficiency, blazed gratings from opposite sectors are oriented to disperse to a LGML forming a channel covering the wavelength range from 35 Å to 75 Å (165 - 350 eV). Upon satellite rotation, the intensities of the dispersed spectra, after reflection and polarizing by the LGMLs, give the three Stokes parameters needed to determine a source’s linear polarization fraction and orientation. The design can be extended to higher energies as LGMLs are developed further. We describe examples of the potential scientific return from instruments based on this design.}, author = {Marshall, Herman L. and Heine, Sarah and Garner, Alan and Gullikson, Eric and Guenther, Moritz and Leitz, Christopher and Masterson, Rebecca and Miller, Eric and Zhang, William and Boissay Malaquin, Rozenn and Caiazzo, Ilaria and Chakrabarty, Deepto and Davidson, Rosemary and Gallo, Luigi and Heilmann, Ralf K. and Heyl, Jeremy and Kara, Erin and Marscher, Alan and Schulz, Norbert}, booktitle = {Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray}, isbn = {978-151063675-0}, issn = {1996-756X}, location = {Virtual}, publisher = {SPIE}, title = {{A small satellite version of a soft x-ray polarimeter}}, doi = {10.1117/12.2562811}, volume = {11444}, year = {2020}, } @inproceedings{15229, abstract = {We propose a high-time-resolution, high-spectral-resolution X-ray telescope that uses transition-edge sensors (TES) as detectors and collector optics to direct the X-rays onto the focal plane, providing a large effective area in a small satellite. The key science driver of the instrument is to study neutron stars and accreting black holes. The proposed instrument is built upon two technologies that are already at high TRL: TES X-ray detectors and collector optics.}, author = {Heyl, Jeremy and Caiazzo, Ilaria and Gallagher, Sarah and Hoffman, Kelsey and Safi-Harb, Samar}, booktitle = {Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray}, isbn = {978-151063675-0}, issn = {1996-756X}, location = {Virtual}, publisher = {SPIE}, title = {{The Colibrì high-resolution x-ray telescope}}, doi = {10.1117/12.2562625}, volume = {11444}, year = {2020}, } @article{15286, author = {Fäßler, Florian and Dimchev, Georgi A and Hodirnau, Victor-Valentin and Zens, Bettina and Möhl, Christoph and Bradke, Frank and Schur, Florian KM}, issn = {1435-8115}, journal = {Microscopy and Microanalysis}, keywords = {Instrumentation}, number = {S2}, pages = {2518--2519}, publisher = {Oxford University Press}, title = {{Cryo-electron tomography workflows for quantitative analysis of actin networks involved in cell migration}}, doi = {10.1017/s1431927620021881}, volume = {26}, year = {2020}, } @article{19306, author = {Kazatskaya, Anna and Yuan, Lisa and Amin-Wetzel, Niko Paresh and Philbrook, Alison and de Bono, Mario and Sengupta, Piali}, issn = {2578-9430}, journal = {microPublication Biology}, number = {9}, publisher = {Caltech Library}, title = {{The URX oxygen-sensing neurons in C. elegans are ciliated}}, doi = {10.17912/MICROPUB.BIOLOGY.000303}, volume = {2020}, year = {2020}, } @article{5681, abstract = {We introduce dynamically warping grids for adaptive liquid simulation. Our primary contributions are a strategy for dynamically deforming regular grids over the course of a simulation and a method for efficiently utilizing these deforming grids for liquid simulation. Prior work has shown that unstructured grids are very effective for adaptive fluid simulations. However, unstructured grids often lead to complicated implementations and a poor cache hit rate due to inconsistent memory access. Regular grids, on the other hand, provide a fast, fixed memory access pattern and straightforward implementation. Our method combines the advantages of both: we leverage the simplicity of regular grids while still achieving practical and controllable spatial adaptivity. We demonstrate that our method enables adaptive simulations that are fast, flexible, and robust to null-space issues. At the same time, our method is simple to implement and takes advantage of existing highly-tuned algorithms.}, author = {Hikaru, Ibayashi and Wojtan, Christopher J and Thuerey, Nils and Igarashi, Takeo and Ando, Ryoichi}, issn = {1941-0506}, journal = {IEEE Transactions on Visualization and Computer Graphics}, number = {6}, pages = {2288--2302}, publisher = {IEEE}, title = {{Simulating liquids on dynamically warping grids}}, doi = {10.1109/TVCG.2018.2883628}, volume = {26}, year = {2020}, } @article{6184, abstract = {We prove edge universality for a general class of correlated real symmetric or complex Hermitian Wigner matrices with arbitrary expectation. Our theorem also applies to internal edges of the self-consistent density of states. In particular, we establish a strong form of band rigidity which excludes mismatches between location and label of eigenvalues close to internal edges in these general models.}, author = {Alt, Johannes and Erdös, László and Krüger, Torben H and Schröder, Dominik J}, issn = {0091-1798}, journal = {Annals of Probability}, number = {2}, pages = {963--1001}, publisher = {Institute of Mathematical Statistics}, title = {{Correlated random matrices: Band rigidity and edge universality}}, doi = {10.1214/19-AOP1379}, volume = {48}, year = {2020}, } @article{6185, abstract = {For complex Wigner-type matrices, i.e. Hermitian random matrices with independent, not necessarily identically distributed entries above the diagonal, we show that at any cusp singularity of the limiting eigenvalue distribution the local eigenvalue statistics are universal and form a Pearcey process. Since the density of states typically exhibits only square root or cubic root cusp singularities, our work complements previous results on the bulk and edge universality and it thus completes the resolution of the Wigner–Dyson–Mehta universality conjecture for the last remaining universality type in the complex Hermitian class. Our analysis holds not only for exact cusps, but approximate cusps as well, where an extended Pearcey process emerges. As a main technical ingredient we prove an optimal local law at the cusp for both symmetry classes. This result is also the key input in the companion paper (Cipolloni et al. in Pure Appl Anal, 2018. arXiv:1811.04055) where the cusp universality for real symmetric Wigner-type matrices is proven. The novel cusp fluctuation mechanism is also essential for the recent results on the spectral radius of non-Hermitian random matrices (Alt et al. in Spectral radius of random matrices with independent entries, 2019. arXiv:1907.13631), and the non-Hermitian edge universality (Cipolloni et al. in Edge universality for non-Hermitian random matrices, 2019. arXiv:1908.00969).}, author = {Erdös, László and Krüger, Torben H and Schröder, Dominik J}, issn = {1432-0916}, journal = {Communications in Mathematical Physics}, pages = {1203--1278}, publisher = {Springer Nature}, title = {{Cusp universality for random matrices I: Local law and the complex Hermitian case}}, doi = {10.1007/s00220-019-03657-4}, volume = {378}, year = {2020}, } @article{6358, abstract = {We study dynamical optimal transport metrics between density matricesassociated to symmetric Dirichlet forms on finite-dimensional C∗-algebras. Our settingcovers arbitrary skew-derivations and it provides a unified framework that simultaneously generalizes recently constructed transport metrics for Markov chains, Lindblad equations, and the Fermi Ornstein–Uhlenbeck semigroup. We develop a non-nommutative differential calculus that allows us to obtain non-commutative Ricci curvature bounds, logarithmic Sobolev inequalities, transport-entropy inequalities, andspectral gap estimates.}, author = {Carlen, Eric A. and Maas, Jan}, issn = {1572-9613}, journal = {Journal of Statistical Physics}, number = {2}, pages = {319--378}, publisher = {Springer Nature}, title = {{Non-commutative calculus, optimal transport and functional inequalities in dissipative quantum systems}}, doi = {10.1007/s10955-019-02434-w}, volume = {178}, year = {2020}, } @article{6359, abstract = {The strong rate of convergence of the Euler-Maruyama scheme for nondegenerate SDEs with irregular drift coefficients is considered. In the case of α-Hölder drift in the recent literature the rate α/2 was proved in many related situations. By exploiting the regularising effect of the noise more efficiently, we show that the rate is in fact arbitrarily close to 1/2 for all α>0. The result extends to Dini continuous coefficients, while in d=1 also to all bounded measurable coefficients.}, author = {Dareiotis, Konstantinos and Gerencser, Mate}, issn = {1083-6489}, journal = {Electronic Journal of Probability}, publisher = {Institute of Mathematical Statistics}, title = {{On the regularisation of the noise for the Euler-Maruyama scheme with irregular drift}}, doi = {10.1214/20-EJP479}, volume = {25}, year = {2020}, } @article{19807, abstract = {Microstructures can be carefully designed to reveal the quantum phase of the wave-like nature of electrons in a metal. Here, we report phase-coherent oscillations of out-of-plane magnetoresistance in the layered delafossites PdCoO2 and PtCoO2. The oscillation period is equivalent to that determined by the magnetic flux quantum, h/e, threading an area defined by the atomic interlayer separation and the sample width, where h is Planck’s constant and e is the charge of an electron. The phase of the electron wave function appears robust over length scales exceeding 10 micrometers and persisting up to temperatures of T > 50 kelvin. We show that the experimental signal stems from a periodic field modulation of the out-of-plane hopping. These results demonstrate extraordinary single-particle quantum coherence lengths in delafossites.}, author = {Putzke, Carsten and Bachmann, Maja D. and McGuinness, Philippa and Zhakina, Elina and Sunko, Veronika and Konczykowski, Marcin and Oka, Takashi and Moessner, Roderich and Stern, Ady and König, Markus and Khim, Seunghyun and Mackenzie, Andrew P. and Moll, Philip J.W.}, issn = {1095-9203}, journal = {Science}, number = {6496}, pages = {1234--1238}, publisher = {American Association for the Advancement of Science}, title = {{h/e oscillations in interlayer transport of delafossites}}, doi = {10.1126/science.aay8413}, volume = {368}, year = {2020}, } @article{19812, abstract = {A nearly free electron metal and a Mott insulating state can be thought of as opposite ends of the spectrum of possibilities for the motion of electrons in a solid. Understanding their interaction lies at the heart of the correlated electron problem. In the magnetic oxide metal PdCrO2, nearly free and Mott-localized electrons exist in alternating layers, forming natural heterostructures. Using angle-resolved photoemission spectroscopy, quantitatively supported by a strong coupling analysis, we show that the coupling between these layers leads to an “intertwined” excitation that is a convolution of the charge spectrum of the metallic layer and the spin susceptibility of the Mott layer. Our findings establish PdCrO2 as a model system in which to probe Kondo lattice physics and also open new routes to use the a priori nonmagnetic probe of photoemission to gain insights into the spin susceptibility of correlated electron materials.}, author = {Sunko, Veronika and Mazzola, F. and Kitamura, S. and Khim, S. and Kushwaha, P. and Clark, O. J. and Watson, M. D. and Marković, I. and Biswas, D. and Pourovskii, L. and Kim, T. K. and Lee, T.-L. and Thakur, P. K. and Rosner, H. and Georges, A. and Moessner, R. and Oka, T. and Mackenzie, A. P. and King, P. D. C.}, issn = {2375-2548}, journal = {Science Advances}, number = {6}, publisher = {American Association for the Advancement of Science}, title = {{Probing spin correlations using angle-resolved photoemission in a coupled metallic/Mott insulator system}}, doi = {10.1126/sciadv.aaz0611}, volume = {6}, year = {2020}, } @article{19817, abstract = {We report a combined experimental and theoretical study of the surface and bulk electronic structure of aluminium diboride, a nonsuperconducting sister compound of the superconductor MgB2. We perform angle-resolved photoemission measurements with variable photon energy, and compare them to density functional theory calculations to disentangle the surface and bulk contributions to the measured spectra. Aluminium diboride is known to be aluminium deficient, Al1−𝛿⁢B2, which would be expected to lead to a hole doping as compared to the nominally stoichimoetric compound. Nonetheless, we find that the bulk 𝜎 states, which mediate superconductivity in MgB2, remain more than 600meV below the Fermi level. However, we also observe 𝜎 states originating from the boron terminated surface, with an order of magnitude smaller binding energy of 70meV, and demonstrate how surface hole-doping can bring these across the Fermi level.}, author = {Sunko, Veronika and Milosavljević, D. and Mazzola, F. and Clark, O. J. and Burkhardt, U. and Kim, T. K. and Rosner, H. and Grin, Yu. and Mackenzie, A. P. and King, P. D. C.}, issn = {2469-9969}, journal = {Physical Review B}, number = {3}, publisher = {American Physical Society}, title = {{Surface and bulk electronic structure of aluminium diboride}}, doi = {10.1103/physrevb.102.035143}, volume = {102}, year = {2020}, } @article{19823, abstract = {The delafossite metals PdCoO2, PtCoO2, and PdCrO2 are among the highest conductivity materials known, with low-temperature mean free paths of tens of microns in the best as-grown single crystals. A key question is whether these very low resistive scattering rates result from strongly suppressed backscattering due to special features of the electronic structure or are a consequence of highly unusual levels of crystalline perfection. We report the results of experiments in which high-energy electron irradiation was used to introduce point disorder to the Pd and Pt layers in which the conduction occurs. We obtain the cross section for formation of Frenkel pairs in absolute units, and cross-check our analysis with first-principles calculations of the relevant atomic displacement energies. We observe an increase of resistivity that is linear in defect density with a slope consistent with scattering in the unitary limit. Our results enable us to deduce that the as-grown crystals contain extremely low levels of in-plane defects of approximately 0.001%. This confirms that crystalline perfection is the most important factor in realizing the long mean free paths and highlights how unusual these delafossite metals are in comparison with the vast majority of other multicomponent oxides and alloys. We discuss the implications of our findings for future materials research.}, author = {Sunko, Veronika and McGuinness, P. H. and Chang, C. S. and Zhakina, E. and Khim, S. and Dreyer, C. E. and Konczykowski, M. and Borrmann, H. and Moll, P. J. W. and König, M. and Muller, D. A. and Mackenzie, A. P.}, issn = {2160-3308}, journal = {Physical Review X}, number = {2}, publisher = {American Physical Society}, title = {{Controlled introduction of defects to delafossite metals by electron irradiation}}, doi = {10.1103/physrevx.10.021018}, volume = {10}, year = {2020}, } @inbook{19986, abstract = {For non-probabilistic programs, a key question in static analysis is termination, which asks whether a given program terminates under a given initial condition. In the presence of probabilistic behaviour, there are two fundamental extensions of the termination question: (a) the almost-sure termination question, which asks whether the termination probability is 1; and (b) the bounded-time termination question, which asks whether the expected termination time is bounded. There are many active research directions to address these two questions; one important such direction is the use of martingale theory for termination analysis. In this chapter, we survey the main techniques of the martingale-based approach to the termination analysis of probabilistic programs.}, author = {Chatterjee, Krishnendu and Fu, Hongfei and Novotný, Petr}, booktitle = {Foundations of Probabilistic Programming}, isbn = {9781108488518}, pages = {221--258}, publisher = {Cambridge University Press}, title = {{Termination Analysis of Probabilistic Programs with Martingales}}, doi = {10.1017/9781108770750.008}, year = {2020}, } @article{20766, abstract = {Reversible catalytic reactions operate under thermodynamic control, and thus, establishing a selective catalytic system poses a considerable challenge. Herein, we report a reversible transfer hydrocyanation protocol that exhibits high selectivity for the thermodynamically less favorable branched isomer. Selectivity is achieved by exploiting the lower barrier for C–CN oxidative addition and reductive elimination at benzylic positions in the absence of a cocatalytic Lewis acid. Through the design of a novel type of HCN donor, a practical, branched-selective, HCN-free transfer hydrocyanation was realized. The synthetically useful resolution of a mixture of branched and linear nitrile isomers was also demonstrated to underline the value of reversible and selective transfer reactions. In a broader context, this work demonstrates that high kinetic selectivity can be achieved in reversible transfer reactions, thus opening new horizons for their synthetic applications.}, author = {Bhawal, Benjamin N. and Reisenbauer, Julia and Ehinger, Christian and Morandi, Bill}, issn = {1520-5126}, journal = {Journal of the American Chemical Society}, number = {25}, pages = {10914--10920}, publisher = {American Chemical Society}, title = {{Overcoming selectivity issues in reversible catalysis: A transfer hydrocyanation exhibiting high kinetic control}}, doi = {10.1021/jacs.0c03184}, volume = {142}, year = {2020}, } @article{20806, abstract = {Regulation of phosphatidylinositol phosphates plays a crucial role in signal transduction, membrane trafficking or autophagy. Members of the myotubularin family of lipid phosphatases contribute to phosphoinositide metabolism by counteracting the activity of phosphoinositide kinases. The mechanisms determining their subcellular localization and targeting to specific membrane compartments are still poorly understood. We show here that the inactive phosphatase MTMR9 localizes to the intermediate compartment and to the Golgi apparatus and is able to recruit its active phosphatase partners MTMR6 and MTMR8 to these locations. Furthermore, MTMR8 and MTMR9 co-localize with the small GTPase RAB1A and regulate its localization. Loss of MTMR9 expression compromises the integrity of the Golgi apparatus and results in altered distribution of RAB1A and actin nucleation-promoting factor WHAMM. Loss or overexpression of MTMR9 leads to decreased rate of protein secretion. We demonstrate that secretion of physiologically relevant cargo exemplified by the WNT3A protein is affected after perturbation of MTMR9 levels.}, author = {Doubravská, Lenka and Dostál, Vojtěch and Knop, Filip and Libusová, Lenka and Macůrková, Marie}, issn = {0014-4827}, journal = {Experimental Cell Research}, number = {1}, publisher = {Elsevier}, title = {{Human myotubularin-related protein 9 regulates ER-to-Golgi trafficking and modulates WNT3A secretion}}, doi = {10.1016/j.yexcr.2019.111709}, volume = {386}, year = {2020}, } @unpublished{10012, abstract = {We prove that in the absence of topological changes, the notion of BV solutions to planar multiphase mean curvature flow does not allow for a mechanism for (unphysical) non-uniqueness. Our approach is based on the local structure of the energy landscape near a classical evolution by mean curvature. Mean curvature flow being the gradient flow of the surface energy functional, we develop a gradient-flow analogue of the notion of calibrations. Just like the existence of a calibration guarantees that one has reached a global minimum in the energy landscape, the existence of a "gradient flow calibration" ensures that the route of steepest descent in the energy landscape is unique and stable.}, author = {Fischer, Julian L and Hensel, Sebastian and Laux, Tim and Simon, Thilo}, booktitle = {arXiv}, title = {{The local structure of the energy landscape in multiphase mean curvature flow: weak-strong uniqueness and stability of evolutions}}, doi = {10.48550/arXiv.2003.05478}, year = {2020}, } @unpublished{10022, abstract = {We consider finite-volume approximations of Fokker-Planck equations on bounded convex domains in R^d and study the corresponding gradient flow structures. We reprove the convergence of the discrete to continuous Fokker-Planck equation via the method of Evolutionary Γ-convergence, i.e., we pass to the limit at the level of the gradient flow structures, generalising the one-dimensional result obtained by Disser and Liero. The proof is of variational nature and relies on a Mosco convergence result for functionals in the discrete-to-continuum limit that is of independent interest. Our results apply to arbitrary regular meshes, even though the associated discrete transport distances may fail to converge to the Wasserstein distance in this generality.}, author = {Forkert, Dominik L and Maas, Jan and Portinale, Lorenzo}, booktitle = {arXiv}, title = {{Evolutionary Γ-convergence of entropic gradient flow structures for Fokker-Planck equations in multiple dimensions}}, doi = {10.48550/arXiv.2008.10962}, year = {2020}, } @inproceedings{10328, abstract = {We discus noise channels in coherent electro-optic up-conversion between microwave and optical fields, in particular due to optical heating. We also report on a novel configuration, which promises to be flexible and highly efficient.}, author = {Lambert, Nicholas J. and Mobassem, Sonia and Rueda Sanchez, Alfredo R and Schwefel, Harald G.L.}, booktitle = {OSA Quantum 2.0 Conference}, isbn = {9-781-5575-2820-9}, location = {Washington, DC, United States}, publisher = {Optica Publishing Group}, title = {{New designs and noise channels in electro-optic microwave to optical up-conversion}}, doi = {10.1364/QUANTUM.2020.QTu8A.1}, year = {2020}, } @article{10336, abstract = {Biological membranes can dramatically accelerate the aggregation of normally soluble protein molecules into amyloid fibrils and alter the fibril morphologies, yet the molecular mechanisms through which this accelerated nucleation takes place are not yet understood. Here, we develop a coarse-grained model to systematically explore the effect that the structural properties of the lipid membrane and the nature of protein–membrane interactions have on the nucleation rates of amyloid fibrils. We identify two physically distinct nucleation pathways—protein-rich and lipid-rich—and quantify how the membrane fluidity and protein–membrane affinity control the relative importance of those molecular pathways. We find that the membrane’s susceptibility to reshaping and being incorporated into the fibrillar aggregates is a key determinant of its ability to promote protein aggregation. We then characterize the rates and the free-energy profile associated with this heterogeneous nucleation process, in which the surface itself participates in the aggregate structure. Finally, we compare quantitatively our data to experiments on membrane-catalyzed amyloid aggregation of α-synuclein, a protein implicated in Parkinson’s disease that predominately nucleates on membranes. More generally, our results provide a framework for understanding macromolecular aggregation on lipid membranes in a broad biological and biotechnological context.}, author = {Krausser, Johannes and Knowles, Tuomas P. J. and Šarić, Anđela}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences}, number = {52}, pages = {33090--33098}, publisher = {National Academy of Sciences}, title = {{Physical mechanisms of amyloid nucleation on fluid membranes}}, doi = {10.1073/pnas.2007694117}, volume = {117}, year = {2020}, }