@article{13350, abstract = {Confinement within molecular cages can dramatically modify the physicochemical properties of the encapsulated guest molecules, but such host-guest complexes have mainly been studied in a static context. Combining confinement effects with fast guest exchange kinetics could pave the way toward stimuli-responsive supramolecular systems—and ultimately materials—whose desired properties could be tailored “on demand” rapidly and reversibly. Here, we demonstrate rapid guest exchange between inclusion complexes of an open-window coordination cage that can simultaneously accommodate two guest molecules. Working with two types of guests, anthracene derivatives and BODIPY dyes, we show that the former can substantially modify the optical properties of the latter upon noncovalent heterodimer formation. We also studied the light-induced covalent dimerization of encapsulated anthracenes and found large effects of confinement on reaction rates. By coupling the photodimerization with the rapid guest exchange, we developed a new way to modulate fluorescence using external irradiation.}, author = {Gemen, Julius and Białek, Michał J. and Kazes, Miri and Shimon, Linda J.W. and Feller, Moran and Semenov, Sergey N. and Diskin-Posner, Yael and Oron, Dan and Klajn, Rafal}, issn = {2451-9294}, journal = {Chem}, keywords = {Materials Chemistry, Biochemistry (medical), General Chemical Engineering, Environmental Chemistry, Biochemistry, General Chemistry}, number = {9}, pages = {2362--2379}, publisher = {Elsevier}, title = {{Ternary host-guest complexes with rapid exchange kinetics and photoswitchable fluorescence}}, doi = {10.1016/j.chempr.2022.05.008}, volume = {8}, year = {2022}, } @article{13351, abstract = {Molecular recognition is at the heart of the noncovalent synthesis of supramolecular assemblies and, at higher length scales, supramolecular materials. In a recent publication in Nature, Stoddart and co-workers demonstrate that the formation of host-guest complexes can be catalyzed by one of the simplest possible catalysts: the electron.}, author = {Gemen, Julius and Klajn, Rafal}, issn = {2451-9294}, journal = {Chem}, keywords = {Materials Chemistry, Biochemistry (medical), General Chemical Engineering, Environmental Chemistry, Biochemistry, General Chemistry}, number = {5}, pages = {1183--1186}, publisher = {Elsevier}, title = {{Electron catalysis expands the supramolecular chemist’s toolbox}}, doi = {10.1016/j.chempr.2022.04.022}, volume = {8}, year = {2022}, } @article{13352, abstract = {Optoelectronic effects differentiating absorption of right and left circularly polarized photons in thin films of chiral materials are typically prohibitively small for their direct photocurrent observation. Chiral metasurfaces increase the electronic sensitivity to circular polarization, but their out-of-plane architecture entails manufacturing and performance trade-offs. Here, we show that nanoporous thin films of chiral nanoparticles enable high sensitivity to circular polarization due to light-induced polarization-dependent ion accumulation at nanoparticle interfaces. Self-assembled multilayers of gold nanoparticles modified with L-phenylalanine generate a photocurrent under right-handed circularly polarized light as high as 2.41 times higher than under left-handed circularly polarized light. The strong plasmonic coupling between the multiple nanoparticles producing planar chiroplasmonic modes facilitates the ejection of electrons, whose entrapment at the membrane–electrolyte interface is promoted by a thick layer of enantiopure phenylalanine. Demonstrated detection of light ellipticity with equal sensitivity at all incident angles mimics phenomenological aspects of polarization vision in marine animals. The simplicity of self-assembly and sensitivity of polarization detection found in optoionic membranes opens the door to a family of miniaturized fluidic devices for chiral photonics.}, author = {Cai, Jiarong and Zhang, Wei and Xu, Liguang and Hao, Changlong and Ma, Wei and Sun, Maozhong and Wu, Xiaoling and Qin, Xian and Colombari, Felippe Mariano and de Moura, André Farias and Xu, Jiahui and Silva, Mariana Cristina and Carneiro-Neto, Evaldo Batista and Gomes, Weverson Rodrigues and Vallée, Renaud A. L. and Pereira, Ernesto Chaves and Liu, Xiaogang and Xu, Chuanlai and Klajn, Rafal and Kotov, Nicholas A. and Kuang, Hua}, issn = {1748-3395}, journal = {Nature Nanotechnology}, keywords = {Electrical and Electronic Engineering, Condensed Matter Physics, General Materials Science, Biomedical Engineering, Atomic and Molecular Physics, and Optics, Bioengineering}, number = {4}, pages = {408--416}, publisher = {Springer Nature}, title = {{Polarization-sensitive optoionic membranes from chiral plasmonic nanoparticles}}, doi = {10.1038/s41565-022-01079-3}, volume = {17}, year = {2022}, } @article{13353, abstract = {We show that the optical properties of indigo carmine can be modulated by encapsulation within a coordination cage. Depending on the host/guest molar ratio, the cage can predominantly encapsulate either one or two dye molecules. The 1 : 1 complex is fluorescent, unique for an indigo dye in an aqueous solution. We have also found that binding two dye molecules stabilizes a previously unknown conformation of the cage.}, author = {Yanshyna, Oksana and Avram, Liat and Shimon, Linda J. W. and Klajn, Rafal}, issn = {1364-548X}, journal = {Chemical Communications}, keywords = {Materials Chemistry, Metals and Alloys, Surfaces, Coatings and Films, General Chemistry, Ceramics and Composites, Electronic, Optical and Magnetic Materials, Catalysis}, number = {21}, pages = {3461--3464}, publisher = {Royal Society of Chemistry}, title = {{Coexistence of 1:1 and 2:1 inclusion complexes of indigo carmine}}, doi = {10.1039/d1cc07081a}, volume = {58}, year = {2022}, } @article{13355, abstract = {Supramolecular self-assembly in biological systems holds promise to convert and amplify disease-specific signals to physical or mechanical signals that can direct cell fate. However, it remains challenging to design physiologically stable self-assembling systems that demonstrate tunable and predictable behavior. Here, the use of zwitterionic tetrapeptide modalities to direct nanoparticle assembly under physiological conditions is reported. The self-assembly of gold nanoparticles can be activated by enzymatic unveiling of surface-bound zwitterionic tetrapeptides through matrix metalloprotease-9 (MMP-9), which is overexpressed by cancer cells. This robust nanoparticle assembly is achieved by multivalent, self-complementary interactions of the zwitterionic tetrapeptides. In cancer cells that overexpress MMP-9, the nanoparticle assembly process occurs near the cell membrane and causes size-induced selection of cellular uptake mechanism, resulting in diminished cell growth. The enzyme responsiveness, and therefore, indirectly, the uptake route of the system can be programmed by customizing the peptide sequence: a simple inversion of the two amino acids at the cleavage site completely inactivates the enzyme responsiveness, self-assembly, and consequently changes the endocytic pathway. This robust self-complementary, zwitterionic peptide design demonstrates the use of enzyme-activated electrostatic side-chain patterns as powerful and customizable peptide modalities to program nanoparticle self-assembly and alter cellular response in biological context.}, author = {Huang, Richard H. and Nayeem, Nazia and He, Ye and Morales, Jorge and Graham, Duncan and Klajn, Rafal and Contel, Maria and O'Brien, Stephen and Ulijn, Rein V.}, issn = {1521-4095}, journal = {Advanced Materials}, keywords = {Mechanical Engineering, Mechanics of Materials, General Materials Science}, number = {1}, publisher = {Wiley}, title = {{Self‐complementary zwitterionic peptides direct nanoparticle assembly and enable enzymatic selection of endocytic pathways}}, doi = {10.1002/adma.202104962}, volume = {34}, year = {2022}, } @article{9199, abstract = {We associate a certain tensor product lattice to any primitive integer lattice and ask about its typical shape. These lattices are related to the tangent bundle of Grassmannians and their study is motivated by Peyre's programme on "freeness" for rational points of bounded height on Fano varieties.}, author = {Browning, Timothy D and Horesh, Tal and Wilsch, Florian Alexander}, issn = {1944-7833}, journal = {Algebra & Number Theory}, number = {10}, pages = {2385--2407}, publisher = {Mathematical Sciences Publishers}, title = {{Equidistribution and freeness on Grassmannians}}, doi = {10.2140/ant.2022.16.2385}, volume = {16}, year = {2022}, } @article{9311, abstract = {Partially observable Markov decision processes (POMDPs) are standard models for dynamic systems with probabilistic and nondeterministic behaviour in uncertain environments. We prove that in POMDPs with long-run average objective, the decision maker has approximately optimal strategies with finite memory. This implies notably that approximating the long-run value is recursively enumerable, as well as a weak continuity property of the value with respect to the transition function. }, author = {Chatterjee, Krishnendu and Saona Urmeneta, Raimundo J and Ziliotto, Bruno}, issn = {1526-5471}, journal = {Mathematics of Operations Research}, keywords = {Management Science and Operations Research, General Mathematics, Computer Science Applications}, number = {1}, pages = {100--119}, publisher = {Institute for Operations Research and the Management Sciences}, title = {{Finite-memory strategies in POMDPs with long-run average objectives}}, doi = {10.1287/moor.2020.1116}, volume = {47}, year = {2022}, } @article{9364, abstract = {Let t : Fp → C be a complex valued function on Fp. A classical problem in analytic number theory is bounding the maximum M(t) := max 0≤H

0 there exists a large subset of a ∈ F×p such that for kl a,1,p : x → e((ax+x) / p) we have M(kla,1,p) ≥ (1−ε/√2π + o(1)) log log p, as p→∞. Finally, we prove a result on the growth of the moments of {M (kla,1,p)}a∈F×p. 2020 Mathematics Subject Classification: 11L03, 11T23 (Primary); 14F20, 60F10 (Secondary).}, author = {Bonolis, Dante}, issn = {1469-8064}, journal = {Mathematical Proceedings of the Cambridge Philosophical Society}, number = {3}, pages = {563 -- 590}, publisher = {Cambridge University Press}, title = {{On the size of the maximum of incomplete Kloosterman sums}}, doi = {10.1017/S030500412100030X}, volume = {172}, year = {2022}, } @article{7577, abstract = {Weak convergence of inertial iterative method for solving variational inequalities is the focus of this paper. The cost function is assumed to be non-Lipschitz and monotone. We propose a projection-type method with inertial terms and give weak convergence analysis under appropriate conditions. Some test results are performed and compared with relevant methods in the literature to show the efficiency and advantages given by our proposed methods.}, author = {Shehu, Yekini and Iyiola, Olaniyi S.}, issn = {1563-504X}, journal = {Applicable Analysis}, number = {1}, pages = {192--216}, publisher = {Taylor & Francis}, title = {{Weak convergence for variational inequalities with inertial-type method}}, doi = {10.1080/00036811.2020.1736287}, volume = {101}, year = {2022}, } @article{7791, abstract = {Extending a result of Milena Radnovic and Serge Tabachnikov, we establish conditionsfor two different non-symmetric norms to define the same billiard reflection law.}, author = {Akopyan, Arseniy and Karasev, Roman}, issn = {2199-6768}, journal = {European Journal of Mathematics}, number = {4}, pages = {1309 -- 1312}, publisher = {Springer Nature}, title = {{When different norms lead to same billiard trajectories?}}, doi = {10.1007/s40879-020-00405-0}, volume = {8}, year = {2022}, } @unpublished{8125, abstract = {Context, such as behavioral state, is known to modulate memory formation and retrieval, but is usually ignored in associative memory models. Here, we propose several types of contextual modulation for associative memory networks that greatly increase their performance. In these networks, context inactivates specific neurons and connections, which modulates the effective connectivity of the network. Memories are stored only by the active components, thereby reducing interference from memories acquired in other contexts. Such networks exhibit several beneficial characteristics, including enhanced memory capacity, high robustness to noise, increased robustness to memory overloading, and better memory retention during continual learning. Furthermore, memories can be biased to have different relative strengths, or even gated on or off, according to contextual cues, providing a candidate model for cognitive control of memory and efficient memory search. An external context-encoding network can dynamically switch the memory network to a desired state, which we liken to experimentally observed contextual signals in prefrontal cortex and hippocampus. Overall, our work illustrates the benefits of organizing memory around context, and provides an important link between behavioral studies of memory and mechanistic details of neural circuits.SIGNIFICANCEMemory is context dependent — both encoding and recall vary in effectiveness and speed depending on factors like location and brain state during a task. We apply this idea to a simple computational model of associative memory through contextual gating of neurons and synaptic connections. Intriguingly, this results in several advantages, including vastly enhanced memory capacity, better robustness, and flexible memory gating. Our model helps to explain (i) how gating and inhibition contribute to memory processes, (ii) how memory access dynamically changes over time, and (iii) how context representations, such as those observed in hippocampus and prefrontal cortex, may interact with and control memory processes.}, author = {Podlaski, William F. and Agnes, Everton J. and Vogels, Tim P}, booktitle = {bioRxiv}, publisher = {Cold Spring Harbor Laboratory}, title = {{High capacity and dynamic accessibility in associative memory networks with context-dependent neuronal and synaptic gating}}, doi = {10.1101/2020.01.08.898528}, year = {2022}, } @article{13445, abstract = {Rotation is typically assumed to induce strictly symmetric rotational splitting into the rotational multiplets of pure p- and g-modes. However, for evolved stars exhibiting mixed modes, avoided crossings between different multiplet components are known to yield asymmetric rotational splitting, in particular for near-degenerate mixed-mode pairs, where notional pure p-modes are fortuitously in resonance with pure g-modes. These near-degeneracy effects have been described in subgiants, but their consequences for the characterization of internal rotation in red giants have not previously been investigated in detail, in part owing to theoretical intractability. We employ new developments in the analytic theory of mixed-mode coupling to study these near-resonance phenomena. In the vicinity of the most p-dominated mixed modes, the near-degenerate intrinsic asymmetry from pure rotational splitting increases dramatically over the course of stellar evolution, and it depends strongly on the mode-mixing fraction ζ. We also find that a linear treatment of rotation remains viable for describing the underlying p- and g-modes, even when it does not for the resulting mixed modes undergoing these avoided crossings. We explore observational consequences for potential measurements of asymmetric mixed-mode splitting, which has been proposed as a magnetic-field diagnostic. Finally, we propose improved measurement techniques for rotational characterization, exploiting the linearity of rotational effects on the underlying p/g-modes, while still accounting for these mixed-mode coupling effects.}, author = {Ong, J. M. Joel and Bugnet, Lisa Annabelle and Basu, Sarbani}, issn = {1538-4357}, journal = {The Astrophysical Journal}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {1}, publisher = {American Astronomical Society}, title = {{Mode mixing and rotational splittings. I. Near-degeneracy effects revisited}}, doi = {10.3847/1538-4357/ac97e7}, volume = {940}, year = {2022}, } @article{13451, abstract = {We characterize massive stars (M > 8 M⊙) in the nearby (D ∼ 0.8 Mpc) extremely metal-poor (Z ∼ 5% Z⊙) galaxy Leo A using Hubble Space Telescope ultraviolet (UV), optical, and near-infrared (NIR) imaging along with Keck/Low-Resolution Imaging Spectrograph and MMT/Binospec optical spectroscopy for 18 main-sequence OB stars. We find that: (a) 12 of our 18 stars show emission lines, despite not being associated with an H ii region, suggestive of stellar activity (e.g., mass loss, accretion, binary star interaction), which is consistent with previous predictions of enhanced activity at low metallicity; (b) six are Be stars, which are the first to be spectroscopically studied at such low metallicity—these Be stars have unusual panchromatic SEDs; (c) for stars well fit by the TLUSTY nonlocal thermodynamic equilibrium models, the photometric and spectroscopic values of $\mathrm{log}({T}_{\mathrm{eff}})$ and $\mathrm{log}(g)$ agree to within ∼0.01 dex and ∼0.18 dex, respectively, indicating that near-UV/optical/NIR imaging can be used to reliably characterize massive (M ∼ 8–30 M⊙) main-sequence star properties relative to optical spectroscopy; (d) the properties of the most-massive stars in H II regions are consistent with constraints from previous nebular emission line studies; and (e) 13 stars with M > 8M⊙ are >40 pc from a known star cluster or H II region. Our sample comprises ∼50% of all known massive stars at Z ≲ 10% Z⊙with derived stellar parameters, high-quality optical spectra, and panchromatic photometry.}, author = {Gull, Maude and Weisz, Daniel R. and Senchyna, Peter and Sandford, Nathan R. and Choi, Yumi and McLeod, Anna F. and El-Badry, Kareem and Götberg, Ylva Louise Linsdotter and Gilbert, Karoline M. and Boyer, Martha and Dalcanton, Julianne J. and GuhaThakurta, Puragra and Goldman, Steven and Marigo, Paola and McQuinn, Kristen B. W. and Pastorelli, Giada and Stark, Daniel P. and Skillman, Evan and Ting, Yuan-sen and Williams, Benjamin F.}, issn = {1538-4357}, journal = {The Astrophysical Journal}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {2}, publisher = {American Astronomical Society}, title = {{A panchromatic study of massive stars in the extremely metal-poor local group dwarf galaxy Leo A}}, doi = {10.3847/1538-4357/aca295}, volume = {941}, year = {2022}, } @article{13452, abstract = {Magnetic fields can drastically change predictions of evolutionary models of massive stars via mass-loss quenching, magnetic braking, and efficient angular momentum transport, which we aim to quantify in this work. We use the MESA software instrument to compute an extensive main-sequence grid of stellar structure and evolution models, as well as isochrones, accounting for the effects attributed to a surface fossil magnetic field. The grid is densely populated in initial mass (3–60 M⊙), surface equatorial magnetic field strength (0–50 kG), and metallicity (representative of the Solar neighbourhood and the Magellanic Clouds). We use two magnetic braking and two chemical mixing schemes and compare the model predictions for slowly rotating, nitrogen-enriched (‘Group 2’) stars with observations in the Large Magellanic Cloud. We quantify a range of initial field strengths that allow for producing Group 2 stars and find that typical values (up to a few kG) lead to solutions. Between the subgrids, we find notable departures in surface abundances and evolutionary paths. In our magnetic models, chemical mixing is always less efficient compared to non-magnetic models due to the rapid spin-down. We identify that quasi-chemically homogeneous main sequence evolution by efficient mixing could be prevented by fossil magnetic fields. We recommend comparing this grid of evolutionary models with spectropolarimetric and spectroscopic observations with the goals of (i) revisiting the derived stellar parameters of known magnetic stars, and (ii) observationally constraining the uncertain magnetic braking and chemical mixing schemes.}, author = {Keszthelyi, Z and de Koter, A and Götberg, Ylva Louise Linsdotter and Meynet, G and Brands, S A and Petit, V and Carrington, M and David-Uraz, A and Geen, S T and Georgy, C and Hirschi, R and Puls, J and Ramalatswa, K J and Shultz, M E and ud-Doula, A}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, keywords = {Space and Planetary Science, Astronomy and Astrophysics}, number = {2}, pages = {2028--2055}, publisher = {Oxford University Press}, title = {{The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at Solar, LMC, and SMC metallicities}}, doi = {10.1093/mnras/stac2598}, volume = {517}, year = {2022}, } @article{13992, abstract = {Understanding the chirality of molecular reaction pathways is essential for a broad range of fundamental and applied sciences. However, the current ability to probe chirality on the time scale of primary processes underlying chemical reactions remains very limited. Here, we demonstrate time-resolved photoelectron circular dichroism (TRPECD) with ultrashort circularly polarized vacuum-ultraviolet (VUV) pulses from a tabletop source. We demonstrate the capabilities of VUV-TRPECD by resolving the chirality changes in time during the photodissociation of atomic iodine from two chiral molecules. We identify several general key features of TRPECD, which include the ability to probe dynamical chirality along the complete photochemical reaction path, the sensitivity to the local chirality of the evolving scattering potential, and the influence of electron scattering off dissociating photofragments. Our results are interpreted by comparison with high-level ab-initio calculations of transient PECDs from molecular photoionization calculations. Our experimental and theoretical techniques define a general approach to femtochirality.}, author = {Svoboda, Vít and Ram, Niraghatam Bhargava and Baykusheva, Denitsa Rangelova and Zindel, Daniel and Waters, Max D. J. and Spenger, Benjamin and Ochsner, Manuel and Herburger, Holger and Stohner, Jürgen and Wörner, Hans Jakob}, issn = {2375-2548}, journal = {Science Advances}, keywords = {Multidisciplinary}, number = {28}, publisher = {American Association for the Advancement of Science}, title = {{Femtosecond photoelectron circular dichroism of chemical reactions}}, doi = {10.1126/sciadv.abq2811}, volume = {8}, year = {2022}, } @article{13993, abstract = {Photoionization is a process taking place on attosecond time scales. How its properties evolve from isolated particles to the condensed phase is an open question of both fundamental and practical relevance. Here, we review recent work that has advanced the study of photoionization dynamics from atoms to molecules, clusters and the liquid phase. The first measurements of molecular photoionization delays have revealed the attosecond dynamics of electron emission from a molecular shape resonance and their sensitivity to the molecular potential. Using electron-ion coincidence spectroscopy these measurements have been extended from isolated molecules to clusters. A continuous increase of the delays with the water-cluster size has been observed up to a size of 4-5 molecules, followed by a saturation towards larger clusters. Comparison with calculations has revealed a correlation of the time delay with the spatial extension of the created electron hole. Using cylindrical liquid-microjet techniques, these measurements have also been extended to liquid water, revealing a delay relative to isolated water molecules that was very similar to the largest water clusters studied. Detailed modeling based on Monte-Carlo simulations confirmed that these delays are dominated by the contributions of the first two solvation shells, which agrees with the results of the cluster measurements. These combined results open the perspective of experimentally characterizing the delocalization of electronic wave functions in complex systems and studying their evolution on attosecond time scales.}, author = {Gong, Xiaochun and Jordan, Inga and Huppert, Martin and Heck, Saijoscha and Baykusheva, Denitsa Rangelova and Jelovina, Denis and Schild, Axel and Wörner, Hans Jakob}, issn = {2673-2424}, journal = {Chimia}, keywords = {General Medicine, General Chemistry}, number = {6}, pages = {520--528}, publisher = {Swiss Chemical Society}, title = {{Attosecond photoionization dynamics: from molecules over clusters to the liquid phase}}, doi = {10.2533/chimia.2022.520}, volume = {76}, year = {2022}, } @article{13994, abstract = {Ultrafast lasers are an increasingly important tool to control and stabilize emergent phases in quantum materials. Among a variety of possible excitation protocols, a particularly intriguing route is the direct light engineering of microscopic electronic parameters, such as the electron hopping and the local Coulomb repulsion (Hubbard U). In this work, we use time-resolved x-ray absorption spectroscopy to demonstrate the light-induced renormalization of the Hubbard U in a cuprate superconductor, La1.905Ba0.095CuO4. We show that intense femtosecond laser pulses induce a substantial redshift of the upper Hubbard band while leaving the Zhang-Rice singlet energy unaffected. By comparing the experimental data to time-dependent spectra of single- and three-band Hubbard models, we assign this effect to an approximately 140-meV reduction of the on-site Coulomb repulsion on the copper sites. Our demonstration of a dynamical Hubbard U renormalization in a copper oxide paves the way to a novel strategy for the manipulation of superconductivity and magnetism as well as to the realization of other long-range-ordered phases in light-driven quantum materials.}, author = {Baykusheva, Denitsa Rangelova and Jang, Hoyoung and Husain, Ali A. and Lee, Sangjun and TenHuisen, Sophia F. R. and Zhou, Preston and Park, Sunwook and Kim, Hoon and Kim, Jin-Kwang and Kim, Hyeong-Do and Kim, Minseok and Park, Sang-Youn and Abbamonte, Peter and Kim, B. J. and Gu, G. D. and Wang, Yao and Mitrano, Matteo}, issn = {2160-3308}, journal = {Physical Review X}, keywords = {General Physics and Astronomy}, number = {1}, publisher = {American Physical Society}, title = {{Ultrafast renormalization of the on-site Coulomb repulsion in a cuprate superconductor}}, doi = {10.1103/physrevx.12.011013}, volume = {12}, year = {2022}, } @inproceedings{14093, abstract = { We propose a stochastic conditional gradient method (CGM) for minimizing convex finite-sum objectives formed as a sum of smooth and non-smooth terms. Existing CGM variants for this template either suffer from slow convergence rates, or require carefully increasing the batch size over the course of the algorithm’s execution, which leads to computing full gradients. In contrast, the proposed method, equipped with a stochastic average gradient (SAG) estimator, requires only one sample per iteration. Nevertheless, it guarantees fast convergence rates on par with more sophisticated variance reduction techniques. In applications we put special emphasis on problems with a large number of separable constraints. Such problems are prevalent among semidefinite programming (SDP) formulations arising in machine learning and theoretical computer science. We provide numerical experiments on matrix completion, unsupervised clustering, and sparsest-cut SDPs. }, author = {Dresdner, Gideon and Vladarean, Maria-Luiza and Rätsch, Gunnar and Locatello, Francesco and Cevher, Volkan and Yurtsever, Alp}, booktitle = {Proceedings of the 25th International Conference on Artificial Intelligence and Statistics}, issn = {2640-3498}, location = {Virtual}, pages = {8439--8457}, publisher = {ML Research Press}, title = {{ Faster one-sample stochastic conditional gradient method for composite convex minimization}}, volume = {151}, year = {2022}, } @article{14098, abstract = {Magnetic fields can drastically change predictions of evolutionary models of massive stars via mass-loss quenching, magnetic braking, and efficient angular momentum transport, which we aim to quantify in this work. We use the MESA software instrument to compute an extensive main-sequence grid of stellar structure and evolution models, as well as isochrones, accounting for the effects attributed to a surface fossil magnetic field. The grid is densely populated in initial mass (3–60 M⊙), surface equatorial magnetic field strength (0–50 kG), and metallicity (representative of the Solar neighbourhood and the Magellanic Clouds). We use two magnetic braking and two chemical mixing schemes and compare the model predictions for slowly rotating, nitrogen-enriched (‘Group 2’) stars with observations in the Large Magellanic Cloud. We quantify a range of initial field strengths that allow for producing Group 2 stars and find that typical values (up to a few kG) lead to solutions. Between the subgrids, we find notable departures in surface abundances and evolutionary paths. In our magnetic models, chemical mixing is always less efficient compared to non-magnetic models due to the rapid spin-down. We identify that quasi-chemically homogeneous main sequence evolution by efficient mixing could be prevented by fossil magnetic fields. We recommend comparing this grid of evolutionary models with spectropolarimetric and spectroscopic observations with the goals of (i) revisiting the derived stellar parameters of known magnetic stars, and (ii) observationally constraining the uncertain magnetic braking and chemical mixing schemes.}, author = {Keszthelyi, Z. and Koter, A. de and Götberg, Ylva Louise Linsdotter and Meynet, G. and Brands, S. A. and Petit, V. and Carrington, M. and A. David-Uraz, A. David-Uraz and Geen, S. T. and Georgy, C. and Hirschi, R. and Puls, J. and Ramalatswa, K. J. and Shultz, M. E. and A. ud-Doula, A. ud-Doula}, issn = {1365-2966}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {2}, pages = {2028--2055}, publisher = {Oxford Academic}, title = {{The effects of surface fossil magnetic fields on massive star evolution: IV. Grids of models at solar, LMC, and SMC metallicities}}, doi = {10.1093/mnras/stac2598}, volume = {517}, year = {2022}, } @unpublished{14099, abstract = {Magnetism can greatly impact the evolution of stars. In some stars with OBA spectral types there is direct evidence via the Zeeman effect for stable, large-scale magnetospheres, which lead to the spin-down of the stellar surface and reduced mass loss. So far, a comprehensive grid of stellar structure and evolution models accounting for these effects was lacking. For this reason, we computed and studied models with two magnetic braking and two chemical mixing schemes in three metallicity environments with the MESA software instrument. We find notable differences between the subgrids, which affects the model predictions and thus the detailed characterisation of stars. We are able to quantify the impact of magnetic fields in terms of preventing quasi-chemically homogeneous evolution and producing slowly-rotating, nitrogen-enriched ("Group 2") stars. Our model grid is fully open access and open source.}, author = {Keszthelyi, Z. and Koter, A. de and Götberg, Ylva Louise Linsdotter and Meynet, G. and Brands, S. A. and Petit, V. and Carrington, M. and A. David-Uraz, A. David-Uraz and Geen, S. T. and Georgy, C. and Hirschi, R. and Puls, J. and Ramalatswa, K. J. and Shultz, M. E. and A. ud-Doula, A. ud-Doula}, booktitle = {arXiv}, title = {{Spin-down and reduced mass loss in early-type stars with large-scale magnetic fields}}, doi = {10.48550/arXiv.2211.07060}, year = {2022}, }