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Калориметрическое и спектроскопическое исследование квазиодномерных халдейновских магнетиков (Y1-xNdx)2BaNiO5 (x = 1, 0.75, 0.50, 0.25)
Журнал экспериментальной и теоретической физики. 2010. Т. 138. № 2(8). С. 231–235.
Loubenets E. R., / Series arxiv.org "quant-ph". 2026. No. 2607.18050.
In many quantum applications it is important to know whether or not a Bell nonlocal two-qudit state exhibits its nonlocality under correlation scenarios with some given numbers S1,S2≥1 of generalized quantum measurements at two sites. In the present article, we find analytically a new general locality condition sufficient for a nonseparable Werner state with a ...
Added: July 21, 2026
Bolbachan V., / Series math "arxiv.org". 2024.
Chow polylogarithms are some special functions arising in explicit description of the Beilinson regulator map. The most interesting functional equation for this function reflects its vanishing on the boundary in the Bloch's cycle complex. We show that this functional equation formally follows from more simple ones, namely skew-symmetry, functoriality and multiplicativity.
To prove this, we study ...
Added: July 16, 2026
Bolbachan V., / Series math "arxiv.org". 2024.
Let K be a field of characteristic zero. We prove that its motivic cohomology in degree m−1 and weight m is rationally isomorphic to the cohomology of the polylogarithmic complex. This gives a partial extension of A. Suslin theorem describing the indecomposable K3 of a field. ...
Added: July 16, 2026
Panov V., Ryabchenko A., / Series arXiv "stat.ME". 2026. No. 2607.05048.
This paper investigates the problem of statistical inference for a mixture distribution consisting of a discrete and a continuous component, with a particular focus on the class of rational-infinitely divisible distributions. We consider non-parametric estimation of both components of the mixture as well as the quasi-L{é}vy measure, assuming that the mixture belongs to the class ...
Added: July 9, 2026
Konakov V., Kucher D., Mammen E., / Series arXiv "math". 2026. No. 2606.11142v1.
In this paper, we construct strong approximations for discrete-time Markov chains weakly converging to continuous diffusion processes, as well as for their perturbed counterparts. Under the assumption of bounded coefficients, we construct closely coupled versions of these processes on a shared probability space. In particular, for both non-degenerate and degenerate cases, we maximize the probability ...
Added: June 11, 2026
Dorovskiy A., / Series arXiv "math". 2026.
In this paper the structural stability of generic families of vector fields of the PC-HC class on the two-dimensional sphere is proved. A classification of these families up to moderate equivalence in neighborhoods of their large bifurcation supports is presented, based on such invariants as the configuration and the characteristic set. The realization lemma is proved. ...
Added: May 14, 2026
Taletskii D., / Series arXiv "math". 2026.
A vertex subset of a graph is called a \textit{distance-$k$ independent set} if the distance between any two of its distinct vertices is at least $k + 1$. For all $n,k \geq 1$, we determine the minimum possible number of inclusion-wise maximal distance-$k$ independent sets among all $n$-vertex trees. It equals~$n$ if $n \leq k ...
Added: May 1, 2026
Ovcharenko M., / Series arXiv "math". 2026.
We introduce an explicit class of tempered Laurent polynomials in the sense of Villegas and Doran--Kerr in n⩽4 variables including all Landau--Ginzburg models for smooth Fano threefolds with very ample anticanonical class. We check that it contains Landau--Ginzburg models for various Fano fourfolds which are complete intersections in smooth toric varieties and Grassmannians of planes, ...
Added: April 30, 2026
Zlotnik Alexander, / Series arXiv "math". 2026. No. 2602.03481v1.
We deal with the global in time weak solutions to the 1D compressible Navier-Stokes system of equations for large discontinuous initial data and nonhomogeneous boundary conditions of three standard types. We prove the Lipschitz-type continuous dependence of the solution $(\eta,u,\theta)$, in a norm slightly stronger than $L^{2,\infty}(Q)\times L^2(Q)\times L^2(Q)$, on the initial data $(\eta^0,u^0,e^0)$ in a ...
Added: April 18, 2026
Medvedev V., / Series arXiv "math". 2026.
We investigate the interplay between the dimension of the space of static potentials and the geometric and topological structure of the underlying static three-manifold. A partial classification of boundaryless static manifolds is obtained in terms of this dimension. We also treat the case of static manifolds with boundary. In particular, we prove that if a ...
Added: April 3, 2026
Gabdullin N., Androsov I., / Series Computer Science "arxiv.org". 2026.
Label prediction in neural networks (NNs) has O(n) complexity proportional to the number of classes. This holds true for classification using fully connected layers and cosine similarity with some set of class prototypes. In this paper we show that if NN latent space (LS) geometry is known and possesses specific properties, label prediction complexity can ...
Added: April 2, 2026
Kolesnikov A., / Series arXiv "math". 2025.
We study Blaschke--Santal{ó}-type inequalities for N>=2 sets (functions) and a special class of cost functions. In particular, we prove new results about reduction of the maximization problem for the Blaschke--Santal{ó}-type functional to homogeneous case (functional inequalities on the sphere) and extend the symmetrization argument to the case of N>2 sets.
We also discuss links to the ...
Added: February 13, 2026
Sorokin K., Beketov M., Онучин А. et al., / arxiv.org. Серия cs.SI "Social and Information Networks ". 2025.
Community detection in complex networks is a fundamental problem, open to new approaches in various scientific settings. We introduce a novel community detection method, based on Ricci flow on graphs. Our technique iteratively updates edge weights (their metric lengths) according to their (combinatorial) Foster version of Ricci curvature computed from effective resistance distance between the ...
Added: January 15, 2026
Gaianov N., Parusnikova A., / Cornell University. Серия math "arxiv.org". 2025.
An algebraic q-difference equation is considered. A sufficient condition for the existence of a formal power-logarithmic expansion of a solution to such an equation in the neighborhood of zero is proposed. An example of applying this sufficient condition for constructing a formal expansion of a solution to a certain q-difference analogue of the fifth Painlevé equation ...
Added: December 25, 2025
Popov V., / Series arXiv "math". 2025. No. 2502.01539.
We prove that the variety of flexes of algebraic curves
of degree 3 in the projective plane is an ideal theoretic complete
intersection in the product of a two-dimensional and a nine-dimensional projective spaces. ...
Added: December 16, 2025
Gnetov F., Konakov V., / Series arXiv "math". 2025. No. 2512.04667.
We establish a central limit theorem, a local limit theorem, and a law of large numbers for a natural
random walk on a symmetric space M of non-compact type and rank one. This class of spaces, which
includes the complex and quaternionic hyperbolic spaces and the Cayley hyperbolic plane, generalizes
the real hyperbolic space Hn. Our approach introduces ...
Added: December 5, 2025
Kazakov A., Koryakin V., Safonov K. et al., / Series arXiv "math". 2025.
The Lorenz attractor is the first example of a robustly chaotic non-hyperbolic attractor. Each orbit of such an attractor has a positive top Lyapunov exponent, and this property persists under small perturbations despite possible bifurcations of the attractor. In this paper, we study the boundary of the Lorenz attractor existence region in the Shimizu-Morioka model. ...
Added: December 4, 2025
Sajhulov T. A., Matveev A. A., Demidov V. V. et al., Журнал экспериментальной и теоретической физики 2025 Т. 168 № 4 С. 500–508
A series of SrMnO₃/La₀.₇Sr₀.₃MnO₃ heterostructures with different thicknesses of the antiferromagnetic SrMnO₃ layer were grown by magnetron sputtering. The magnetic characteristics of the SrMnO₃/La₀.₇Sr₀.₃MnO₃ heterostructure, including the magnitude of unidirectional anisotropy at various thicknesses of the antiferromagnetic SrMnO₃ layer, were determined using ferromagnetic resonance. The results of X-ray structural analysis of the obtained samples are ...
Added: November 19, 2025
Popova E., В кн.: СОВРЕМЕННЫЕ ФИЗИКА, МАТЕМАТИКА, ЦИФРОВЫЕ И НАНОТЕХНОЛОГИИ В НАУКЕ И ОБРАЗОВАНИИ (ФМЦН-24) Сборник тезисов III Всероссийской молодежной школы-конференции, посвященной 70-летию со дня рождения профессора Р.М. Асадуллина.: Уфа: Башкирский государственный педагогический университет им. М. Акмуллы, 2024. С. 85–87.
The main motif of the crystal structure of rare earth nickelates (Y1-xRx)2BaNiO5 (R = Gd or Nd) are chains of Ni2+ ions with spin S=1 (Haldane chains) directed along the a axis of the crystal. The interaction between rare earth ions R3+ located between the chains is carried out through spin fluctuations of the nickel ...
Added: March 5, 2025
Popova E., В кн.: Сборник тезисов II Всероссийской молодежной школы-конференции «СОВРЕМЕННЫЕ ФИЗИКА, МАТЕМАТИКА, ЦИФРОВЫЕ И НАНОТЕХНОЛОГИИ В НАУКЕ И ОБРАЗОВАНИИ (ФМЦН-23)», посвященной 80-летию со дня рождения д.ф.-м.н., профессора Р.С.Сингатуллина.: Уфа: Издательство БГПУ, 2023. С. 118–119.
The compounds of the (Y1-xNdx)2BaNiO5 family contain two types of magnetic ions: Ni2+ (S=1) and Nd3+ (J=9/2). The interaction between the magnetic subsystems of the studied compounds with different concentrations of neodymium is manifested in anomalies in the temperature dependence of the heat capacity C(T) and the magnetic susceptibility χ(T). The paper analyzes experimental data ...
Added: March 5, 2025
Popova E., В кн.: Фундаментальная математика и ее приложения в естествознании: спутник Международной научной конференции "Уфимская осенняя математическая школа-2022". Тезисы докладов ХIII Международной школы-конференции студентов, аспирантов и молодых ученых, посвященной 50-летию образования математического и физического факультетов БашГУ.: Уфа: РИЦ БашГУ, 2022. С. 150–150.
In this paper, the field dependences of magnetization M(B) and temperature dependences of heat capacity C(T,B) were investigated for compounds of the (Y1-xNdx)2BaNiO5 family with different concentrations of neodymium in the presence of an external magnetic field ...
Added: March 23, 2023
Popova E., Известия Уфимского научного центра РАН 2023 № 1 С. 75–80
In the compounds of the (Y1-xNdx)2BaNiO5 family, the paradoxical coexistence of the Haldane phase and spin waves is realized. The magnetic ordering in the system is caused by the interaction of Nd3+ ions through spin fluctuations of a nickel chain, which remains internally disordered. Nd3+ magnetic moments do not deviate from the c axis of ...
Added: March 22, 2023
Павлов А. А., Некорн Й., Зубкевич С. В. et al., Inorganic Chemistry 2021 Vol. 59 No. 15 P. 10746–10755
Herein, we combine for the first time SQUID magnetometry, cw-EPR, THz-EPR, and paramagnetic NMR spectroscopies to study the magnetic properties of a high-spin cobalt(II) heteroscorpionate complex. Complementary information provided by these methods allowed precise determination of the magnetic interaction parameters, thereby removing the ambiguity inherit to single-method studies. We systematically investigate the extent to which ...
Added: March 18, 2022
Popova E., Екомасов Е. Г., Известия Уфимского научного центра РАН 2021 № 1 С. 49–55
In a number of quasi-one-dimensional magnets, transition metal ions obeying the motives of the crystal lattice can form chains of integer spins that are distant from each other, named Haldane chains. This paper provides a brief overview of the magnetic properties of Haldane chains and considers some compounds containing such chains. The main features of ...
Added: December 28, 2020