@article{9121,
abstract = {We show that the energy gap for the BCS gap equation is
Ξ=μ(8e−2+o(1))exp(π2μ−−√a)
in the low density limit μ→0. Together with the similar result for the critical temperature by Hainzl and Seiringer (Lett Math Phys 84: 99–107, 2008), this shows that, in the low density limit, the ratio of the energy gap and critical temperature is a universal constant independent of the interaction potential V. The results hold for a class of potentials with negative scattering length a and no bound states.},
author = {Lauritsen, Asbjørn Bækgaard},
issn = {0377-9017},
journal = {Letters in Mathematical Physics},
keywords = {Mathematical Physics, Statistical and Nonlinear Physics},
publisher = {Springer Nature},
title = {{The BCS energy gap at low density}},
doi = {10.1007/s11005-021-01358-5},
volume = {111},
year = {2021},
}
@article{9158,
abstract = {While several tools have been developed to study the ground state of many-body quantum spin systems, the limitations of existing techniques call for the exploration of new approaches. In this manuscript we develop an alternative analytical and numerical framework for many-body quantum spin ground states, based on the disentanglement formalism. In this approach, observables are exactly expressed as Gaussian-weighted functional integrals over scalar fields. We identify the leading contribution to these integrals, given by the saddle point of a suitable effective action. Analytically, we develop a field-theoretical expansion of the functional integrals, performed by means of appropriate Feynman rules. The expansion can be truncated to a desired order to obtain analytical approximations to observables. Numerically, we show that the disentanglement approach can be used to compute ground state expectation values from classical stochastic processes. While the associated fluctuations grow exponentially with imaginary time and the system size, this growth can be mitigated by means of an importance sampling scheme based on knowledge of the saddle point configuration. We illustrate the advantages and limitations of our methods by considering the quantum Ising model in 1, 2 and 3 spatial dimensions. Our analytical and numerical approaches are applicable to a broad class of systems, bridging concepts from quantum lattice models, continuum field theory, and classical stochastic processes.},
author = {De Nicola, Stefano},
issn = {1742-5468},
journal = {Journal of Statistical Mechanics: Theory and Experiment},
keywords = {Statistics, Probability and Uncertainty, Statistics and Probability, Statistical and Nonlinear Physics},
number = {1},
publisher = {IOP Publishing},
title = {{Disentanglement approach to quantum spin ground states: Field theory and stochastic simulation}},
doi = {10.1088/1742-5468/abc7c7},
volume = {2021},
year = {2021},
}
@article{9173,
abstract = {We show that Hilbert schemes of points on supersingular Enriques surface in characteristic 2, Hilbn(X), for n ≥ 2 are simply connected, symplectic varieties but are not irreducible symplectic as the hodge number h2,0 > 1, even though a supersingular Enriques surface is an irreducible symplectic variety. These are the classes of varieties which appear only in characteristic 2 and they show that the hodge number formula for G¨ottsche-Soergel does not hold over haracteristic 2. It also gives examples of varieties with trivial canonical class which are neither irreducible symplectic nor Calabi-Yau, thereby showing that there are strictly more classes of simply connected varieties with trivial canonical class in characteristic 2 than over C as given by Beauville-Bogolomov decomposition theorem.},
author = {Srivastava, Tanya K},
issn = {0007-4497},
journal = {Bulletin des Sciences Mathematiques},
number = {03},
publisher = {Elsevier},
title = {{Pathologies of the Hilbert scheme of points of a supersingular Enriques surface}},
doi = {10.1016/j.bulsci.2021.102957},
volume = {167},
year = {2021},
}
@unpublished{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},
booktitle = {arXiv},
title = {{Equidistribution and freeness on Grassmannians}},
year = {2021},
}
@article{9205,
abstract = {Cryo-EM grid preparation is an important bottleneck in protein structure determination, especially for membrane proteins, typically requiring screening of a large number of conditions. We systematically investigated the effects of buffer components, blotting conditions and grid types on the outcome of grid preparation of five different membrane protein samples. Aggregation was the most common type of problem which was addressed by changing detergents, salt concentration or reconstitution of proteins into nanodiscs or amphipols. We show that the optimal concentration of detergent is between 0.05 and 0.4% and that the presence of a low concentration of detergent with a high critical micellar concentration protects the proteins from denaturation at the air-water interface. Furthermore, we discuss the strategies for achieving an adequate ice thickness, particle coverage and orientation distribution on free ice and on support films. Our findings provide a clear roadmap for comprehensive screening of conditions for cryo-EM grid preparation of membrane proteins.},
author = {Kampjut, Domen and Steiner, Julia and Sazanov, Leonid A},
issn = {25890042},
journal = {iScience},
number = {3},
publisher = {Elsevier},
title = {{Cryo-EM grid optimization for membrane proteins}},
doi = {10.1016/j.isci.2021.102139},
volume = {24},
year = {2021},
}