Miracle-dz/UniFAR-FTUs huggingface dataset:
Making sense of non-Hermitian Hamiltonians

The Hamiltonian H specifies the energy levels and time evolution of a quantum theory. A standard axiom of quantum mechanics requires that H be Hermitian because Hermiticity guarantees that the energy spectrum is real and that time evolution is unitary (probability-preserving). This paper describes an alternative formulation of quantum mechanics in which the mathematical axiom of Hermiticity (transpose +complex conjugate) is replaced by the physically transparent condition of space–time reflection ( ) symmetry. If H has an unbroken symmetry, then the spectrum is real. Examples of -symmetric non-Hermitian quantum-mechanical Hamiltonians are and . Amazingly, the energy levels of these Hamiltonians are all real and positive! Does a -symmetric Hamiltonian H specify a physical quantum theory in which the norms of states are positive and time evolution is unitary? The answer is that if H has an unbroken symmetry, then it has another symmetry represented by a linear operator . In terms of , one can construct a time-independent inner product with a positive-definite norm. Thus, -symmetric Hamiltonians describe a new class of complex quantum theories having positive probabilities and unitary time evolution. The Lee model provides an excellent example of a -symmetric Hamiltonian. The renormalized Lee-model Hamiltonian has a negative-norm ‘ghost’ state because renormalization causes the Hamiltonian to become non-Hermitian. For the past 50 years there have been many attempts to find a physical interpretation for the ghost, but all such attempts failed. The correct interpretation of the ghost is simply that the non-Hermitian Lee-model Hamiltonian is -symmetric. The operator for the Lee model is calculated exactly and in closed form and the ghost is shown to be a physical state having a positive norm. The ideas of symmetry are illustrated by using many quantum-mechanical and quantum-field-theoretic models.
On forests, stable sets and polyhedras associated with clique partitions

Let G = ( V, E ) be a simple graph on n nodes. We show how to construct a partial subgraph D of the line graph of G satisfying the identity: χ ( G ) + α ( D ) = n , where χ ( G ) denotes the minimum number of cliques in a clique partition of G and α ( D ) denotes the maximum size of a stable set of D . This is based on correspondences between the cliques partitions and the clique-connecting forests of G . We use this to develop a cutting-plane algorithm for the graph coloring problem that is tested on random and DIMACS benchmark graphs.
Two-dimensional tunnel bifurcations with dissipation

Two-particle tunneling in synchronous and asynchronous regimes is studied in the framework of dissipative quantum tunneling. We show that the use of the proposed model is justified by a comparison with realistic potential energy surfaces of porphyrin and experimental dependence of the reaction rate on temperature. The critical temperature T_c corresponding to a bifurcation of the underbarrier trajectory is determined. The effect of a heat bath local mode on the probability of two-dimensional tunneling transfer is also investigated. At certain values of the parameters, the degeneracy of antiparallel tunneling trajectories is important. Thus, four, six, twelve, etc., pairs of the trajectories should be taken into account (a cascade of bifurcations). For the parallel particle tunneling the bifurcation resembles phase transition of a first kind, while for the antiparallel transfer it behaves as second order phase transition. The proposed theory allows for the explanation of experimental data on quantum fluctuations in two-proton tunneling in porphyrins near the critical temperature.
The ZH-calculus: completeness and extensions ∗

The ZH-calculus is a graphical calculus for describing and manipulating quantum computations, ﬁrst introduced in [2, QPL’18]. Much like its older cousin, the ZX-calculus [3, 4, 6], it admits straightforward encodings of quantum circuits and several ﬂavours of measurement-based quantum computation (MBQC). However, unlike ZX, ZH is able to elegantly capture and reason about ‘AND-gate like’ structures (e.g. Toffoli gates) arising in quantum computation. As a rough analogy with circuits, diagrams of the ZX-calculus can be seen as an extension of the universal families of Clifford+T or Clifford+Rz circuits, whereas ZH-calculus diagrams most readily extend the (also universal [17]) family of Toffoli+Hadamard circuits. This makes them well-suited for producing efﬁcient decompositions of Toffoli gates using graphical Fourier theory
The 2016 Outburst of PSR J1119-6127: Cooling and a Spin-down-dominated Glitch

We report on the aftermath of a magnetar outburst from the young, high magnetic field radio pulsar PSR J1119−6127 that occurred on 2016 July 27. We present the results of a monitoring campaign using the Neil Gehrels Swift X-ray Telescope, NuSTAR, and XMM-Newton. After reaching a peak absorbed 0.5–10 keV flux of erg cm−2 s−1 on 2016 July 27, the pulsar’s X-ray flux declined by factor of ∼50 to erg cm−2 s−1 on 2016 December 12. The X-ray spectra are well described by a blackbody plus a hard power-law tail. During this time, the blackbody radius decreases monotonically by a factor of ∼4 over a span of nearly 200 days. We also report a highly pulsed hard X-ray emission component, which fades on a similar timescale to the soft X-ray flux, as predicted by models of relaxation of magnetospheric current twists. The previously reported spin-up glitch that accompanied this outburst was followed by a period of enhanced and erratic torque, leading to a net spin down of ∼3.5 × 10−4 Hz, a factor of ∼24 over-recovery. We suggest that this and other radiatively loud magnetar-type glitch recoveries are dominated by magnetospheric processes, in contrast to conventional radio pulsar glitch recoveries which are dominated by internal physics.
Process Simulation and Automated Cost Optimization of CO 2 Capture Using Aspen HYSYS

A standard process for CO 2 capture based on absorption in mono ethanolamine (MEA) has been simulated and cost estimated with an equilibrium-based model in Aspen HYSYS TM . The aim has been to calculate cost optimum process parameters and evaluate the possibility of automated cost optimization using a spreadsheet facility. An Excel spreadsheet is used for dimensioning and cost estimation of the specified process. New in this work is that Visual Basic for Application (VBA) was used to automatically update installation factors for next iteration based on cost calculations in previous iteration. The equipment cost was obtained from the Aspen In-plant Cost Estimator TM , and an enhanced detailed factor (EDF) method was used to estimate the total investment cost. The optimum process was found as the process with minimum calculated total cost. The cost optimum process parameters for the standard process were calculated to 15 m absorber packing height, 9 °C minimum approach temperature and 2.2 m/s superficial gas velocity through the absorber. With this approach, iterative cost estimation and optimization of CO 2 absorption and desorption processes can be performed automatically.
Pairwise likelihood inference for multilevel latent Markov models

We propose an extended latent Markov model for categorical longitudinal data with a multilevel structure. This extension allows us to take into account the correlation which may arise between the responses provided by individuals belonging to the same cluster and to model the cluster effect in a dynamic fashion. Given the complexity of computing the manifest distribution, we make inference on the model through a composite likelihood function based on all the possible pairs of subjects within every cluster. The resulting approach is illustrated through an application to a dataset concerning a sample of Italian workers.
Acupuncture for dry eye disease after recovery from COVID-19: A protocol for systematic review and meta-analysis

Background: Dry eye disease (DED) is a condition occurring worldwide. Studies have found that coronavirus disease 2019 (COVID-19) patients may have persistent dry eye symptoms for weeks and months after recovery, and the prevalence of dry eye is higher in COVID-19 patients than in people without COVID-19 infection. As one of the common ophthalmic diseases, the clinical application of acupuncture in the treatment of DED is not widely used nowadays. Methods: According to the retrieval strategies, randomized controlled trials (RCT) on the acupuncture for DED after recovery from COVID-19 were obtained from Embase, The Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure database, Chinese Biomedical Database, Chinese Science and Technology Periodical database, The WanFang database. Studies were screened based on inclusion and exclusion criteria, and the Cochrane risk bias assessment tool was used to evaluate the quality of the studies. The meta-analysis was performed using Review Manager (RevMan 5.3) and STATA 14.2 software. Ultimately, the evidentiary grade for the results will be evaluated. Results: The study will provide a high-quality and convincing assessment of the efficacy and safety of acupuncture for DED after recovery from COVID-19 and will be published in peer-reviewed journals. Conclusion: Our findings will provide references for future clinical decision and guidance development.
The Quantum of area Delta A = 8 pi l**2(p) and a statistical interpretation of black hole entropy

In contrast to alternative values, the quantum of area $\Delta A = 8\pi l_P^{2}$ does not follow from the usual statistical interpretation of black hole entropy; on the contrary, a statistical interpretation follows from it. This interpretation is based on the two concepts: nonadditivity of black hole entropy and Landau quantization. Using nonadditivity a microcanonical distribution for a black hole is found and it is shown that the statistical weight of black hole should be proportional to its area. By analogy with conventional Landau quantization, it is shown that quantization of black hole is nothing but the Landau quantization. The Landau levels of black hole and their degeneracy are found. The degree of degeneracy is equal to the number of ways to distribute a patch of area $8\pi l_P^{2}$ over the horizon. Taking into account these results, it is argued that the black hole entropy should be of the form $S_{bh} =2\pi\cdot\Delta\Gamma $, where the number of microstates is $\Delta\Gamma = A/8\pi l_P^{2}$. The nature of the degrees of freedom responsible for black hole entropy is elucidated. The applications of the new interpretation are presented. The effect of noncommuting coordinates is discussed.
Controversies in Shoulder Instability

Emphasis on current controversies allows readers to weigh opposing viewpoints and choose the best management strategy for first-time dislocators, multi-directional shoulder instability, stabilization of injuries in a contact athlete, management of SLAP tears, treatment of shoulder injuries in the elderly, and more! Multiple techniques are presented for key disorders allowing readers to select the most appropriate management strategy for each patient. Step-by-step coverage of each procedure ensures proper technique, minimizes error, optimizes results, and reduces post-surgical recovery times. Helpful illustrations highlight key concepts from the text.
A Multi-Feature Deep Learning Algorithm for Urban Traffic Classification with Limited Labeled Data

 Abstract — Acoustic sensors, if embedded in smart street lights, can help in capturing the activities (car honking, sirens, events, traffic, etc.) in cities. Needless to say, the acoustic data from such scenarios are complex due to multiple audio streams originating from different events, and when decomposed to independent signals, the amount of retrieved data volume is small in quantity which is inadequate to train deep neural networks. So, in this paper, we address the two challenges: a) separating the mixed signals, and b) developing an efficient acoustic classifier under data paucity. So, to address these challenges, we propose an architecture with supervised deep learning, where the initial captured mixed acoustics data are analyzed with Fast Fourier Transformation (FFT), followed by filtering the noise from the signal, and then decomposed to independent signals by fast independent component analysis (Fast ICA). To address the challenge of data paucity, we propose a multi feature-based deep neural network with high performance that is reflected in our experiments when compared to the conventional convolutional neural network (CNN) and multi-layer perceptron (MLP).
Combinatorial methods in representation theory

Robinson-Schensted correspondence and left cells by S. Ariki Crystal bases for quantum superalgebras by G. Benkart and S. -J. Kang Approximation results for Kazhdan-Lusztig polynomials by F. Brenti Plane partitions II: $5\tfrac{1}{2}$ symmetry classes by M. Ciucu and C. Krattenthaler Invariants for representations of Weyl groups, two-sided cells, and modular representations of Iwahori-Hecke algebras by A. Gyoja, K. Nishiyama, and K. Taniguchi Finite crystals and paths by G. Hatayama, Y. Koga, A. Kuniba, M. Okado, and T. Takagi Minor summation formulas of Pfaffians, survey and a new identity by M. Ishikawa and M. Wakayama Factorization of Kazhdan-Lusztig elements for Grassmanians by A. Kirillov, Jr. and A. Lascoux Littlewood-Richardson coefficients and Kazhdan-Lusztig polynomials by B. Leclerc and J.-Y. Thibon A weight basis for representations of even orthogonal Lie algebras by A. I. Molev Schur's $Q$-functions and twisted affine Lie algebras by T. Nakajima and H. -F. Yamada Capelli elements in the classical universal enveloping algebras by M. Nazarov On permutation statistics and Hecke algebra characters by Y. Roichman Bosonic formula for level-restricted paths by A. Schilling and M. Shimozono Length functions for $G(r,p,n)$ by T. Shoji Representations of degenerate affine Hecke algebra and $\mathfrak{gl}_n$ by T. Suzuki A recursion formula of the weighted parabolic Kazhdan-Lusztig polynomials by H. Tagawa Special polynomials and generalized Painleve equations by Y. Yamada A duality of a twisted group algebra of the hyperoctahedral group and the queer Lie superalgebra by M. Yamaguchi.
Atomic structure of amorphous and crystallized Ge15Sb85

Ge15Sb85 is a promising material for phase-change memory applications owing to its very short crystallization times. As deposited amorphous samples of sputter deposited Ge15Sb85 have been investigated by extended x-ray absorption fine structure (EXAFS) measurements on both, Sb and Ge K absorption edges. After crystallizing the specimen, x-ray diffraction (XRD) and EXAFS measurements have been performed to analyze the atomic structure at different annealing conditions. Thus, experimental techniques focusing on the long range order as well as on the local order have been combined. Sb atoms have on average 3.2(2) nearest neighbors, while Ge atoms have 4.0(3). The Ge–Ge and Ge–Sb bond lengths are determined to 2.46(2) and 2.66(1) A, respectively and agree well with those observed in the amorphous phase of the common phase-change material Ge2Sb2Te5. After crystallizing the sample at 250 °C, very different EXAFS spectra with modified Ge–Sb bond lengths are observed. The higher concentration of Ge neighbors at the Ge edge as compared to the as-deposited sample is indicative for phase separation. For the corresponding sample, XRD does not show reflections of Ge, which indicates that the agglomeration of Ge is amorphous or below the coherence length of the x-radiation. The EXAFS spectrum shows a superposition of two phases: one with bond lengths which agree with sp3-hybridized Ge [2.43(1) A] and another one with longer Ge–Ge bond lengths [2.79(8) A]. This result can be explained by phase separation in the material.Ge15Sb85 is a promising material for phase-change memory applications owing to its very short crystallization times. As deposited amorphous samples of sputter deposited Ge15Sb85 have been investigated by extended x-ray absorption fine structure (EXAFS) measurements on both, Sb and Ge K absorption edges. After crystallizing the specimen, x-ray diffraction (XRD) and EXAFS measurements have been performed to analyze the atomic structure at different annealing conditions. Thus, experimental techniques focusing on the long range order as well as on the local order have been combined. Sb atoms have on average 3.2(2) nearest neighbors, while Ge atoms have 4.0(3). The Ge–Ge and Ge–Sb bond lengths are determined to 2.46(2) and 2.66(1) A, respectively and agree well with those observed in the amorphous phase of the common phase-change material Ge2Sb2Te5. After crystallizing the sample at 250 °C, very different EXAFS spectra with modified Ge–Sb bond lengths are observed. The higher concentration of Ge neighbors at t.
Flexible Ultrastrong 100-nm Polyethylene Membranes with Polygonal Pore Structures

Robust nanoporous polymer films with approximate 100-nm thicknesses would be broadly applicable in technological areas such as flexible sensors, artificial skins, separators, antireflection and self-cleaning films. However, the creation of these films has been extremely challenging. To date, all reported ultrathin films are of insufficient mechanical strength for use without substrate supports. We describe here the fabrication of a new ultrastrong and highly flexible ultrahigh molecular weight polyethylene (UHMWPE) 100-nm porous membrane. Scanning and transmission electron microscopy evaluations of film microstructures reveal a planar fibrous structure with randomly oriented polygonal interconnected pores. Moreover, the tensile strength of this film is twice as strong as that of solid stainless steel, with a measured in-plane tensile strength and ductility of approximately 900 MPa and 26%, respectively. We further coated our newly developed film with a monolayer graphene to invent an optically transparent and fully conformable piezoresistive skin sensor and thus demonstrated a potential application.
An Investigation and Development of Three Estimators of Inverse Covariance Matrices With Applications to the Mahalanobis Distance

This paper treats the problem of estimating the inverse covariance matrix in an increasing dimension context. Specifically, three ridge-type estimators are considered, of which two new are proposed by the authors and one has been considered previously. Risk functions for deciding an appropriate value of the ridge coefficient are developed and the finite sample properties of the estimators are investigated in a Monte Carlo simulation. Moreover, risk functions for the Mahalanobis distance are derived which, in turn, leads to three new estimators which has not been considered previously
ACCELERATION OF COSMIC RAYS AT LARGE SCALE COSMIC SHOCKS IN THE UNIVERSE

Cosmological hydrodynamic simulations of large scale structure in the universe have shown that accretion shocks and merger shocks form due to flow motions associated with the gravitational collapse of nonlinear structures. Estimated speed and curvature radius of these shocks could be as large as a few 1000 km/s and several Mpc, respectively. According to the diffusive shock acceleration theory, populations of cosmic-ray particles can be injected and accelerated to very high energy by astrophysical shocks in tenuous plasmas. In order to explore the cosmic ray acceleration at the cosmic shocks, we have performed nonlinear numerical simulations of cosmic ray (CR) modified shocks with the newly developed CRASH (Cosmic Ray Amr SHock) numerical code. We adopted the Bohm diffusion model for CRs, based on the hypothesis that strong Alfven waves are self-generated by streaming CRs. The shock formation simulation includes a plasma-physics-based `injection` model that transfers a small proportion of the thermal proton flux through the shock into low energy CRs for acceleration there. We found that, for strong accretion shocks, CRs can absorb most of shock kinetic energy and the accretion shock speed is reduced up to , compared to pure gas dynamic shocks. For merger shocks with small Mach numbers, however, the energy transfer to CRs is only about with an associated CR particle fraction of . Nonlinear feedback due to the CR pressure is insignificant in the latter shocks. Although detailed results depend on models for the particle diffusion and injection, these calculations show that cosmic shocks in large scale structure could provide acceleration sites of extragalactic cosmic rays of the highest energy.
Sampling Rate Independent Filtration Approach for Automatic ECG Delineation

In this paper different types of ECG automatic delineation approaches were overviewed. A combination of these approaches was used to create sampling rate independent filtration algorithm for automatic ECG delineation that is capable of distinguishing different morphologies of T and P waves and QRS complexes. Created filtration algorithm was compared with algorithme \`a trous. It was investigated that continuous wavelets transform with proposed automatic adaptation for different sampling rates procedure can be used for delineation problem.
Comparison of cosmological Boltzmann codes: Are we ready for high precision cosmology?

We compare three independent, cosmological linear perturbation theory codes to asses the level of agreement between them and to improve upon it by investigating the sources of discrepancy. By eliminating the major sources of numerical instability the final level of agreement between the codes was improved by an order of magnitude. The relative error is now below 0.1% for the dark matter power spectrum. For the cosmic microwave background anisotropies the agreement is below the sampling variance up to l=3000, with close to 0.1% accuracy reached over most of this range of scales. The same level of agreement is also achieved for the polarization spectrum and the temperature-polarization cross-spectrum. Linear perturbation theory codes are thus well prepared for the present and upcoming high precision cosmological observations.
Surveying the Giant H ii Regions of the Milky Way with SOFIA. I. W51A

We discuss the first results from our mid-infrared (MIR) imaging survey of Milky Way Giant H ii (GH ii) regions with our detailed analysis of W51A, which is one of the largest GH ii regions in our Galaxy. We used the FORCAST instrument on the Stratospheric Observatory For Infrared Astronomy (SOFIA) to obtain 20 and 37 μm images of the central 10′ × 20′ area, which encompasses both of the G49.5–0.4 and G49.4–0.3 subregions. Based on these new data, and in conjunction with previous multiwavelength observations, we conjecture on the physical nature of several individual sources and subcomponents within W51A. We find that extinction seems to play an important role in the observed structures we see in the near- to MIR, both globally and locally. We used the SOFIA photometry combined with Spitzer–IRAC and Herschel–PACS photometry data to construct spectral energy distributions (SEDs) of the subcomponents and point sources detected in the SOFIA images. We fit those SEDs with young stellar object models and found 41 sources that are likely to be massive young stellar objects, many of which are identified as such in this work for the first time. Close to half of the massive young stellar objects do not have detectable radio continuum emission at centimeter wavelengths, implying a very young state of formation. We derived luminosity-to-mass ratio and virial parameters of the extended radio subregions of W51A to estimate their relative ages.