Conformal Enhancement of Holographic Scaling in Black Hole Thermodynamics: A Near-Horizon Heat-Kernel Framework

Standard thermodynamic treatments of quantum field theory in the presence of black-hole backgrounds reproduce the black hole entropy by usually specializing to the leading order of the heat-kernel or the high-temperature expansion. By contrast, this work develops a hybrid framework centered on geometric spectral asymptotics whereby these assumptions are shown to be unwarranted insofar as black hole thermodynamics is concerned. The approach--consisting of the concurrent use of near-horizon and heat-kernel asymptotic expansions--leads to a proof of the holographic scaling of the entropy as a universal feature driven by conformal quantum mechanics.Comment: 13 pages, JHEP style. Added section 3 in the new version and a few typos were correcte

200 keV electron beam pulse source for the complex VEPP-5 preinjector

The electron beam source based on GS-34 valve cathode-grid unit with oxide cathode of 12 mm in diameter is described. Originally the high voltage DC source was used to supply the gun. The cathode emission characteristic was reduced by the vacuum breakdowns during gun operation. So the necessity of decreasing a high voltage from 200 kV to 140 kV has appeared. The use of the pulse transformer based gun supply with a pulse duration of ~1 mcs provided the gun operation without breakdowns at a voltage of 200 kV and pulse repetition rate up to 50 Hz. At present time the electron source is operated at the complex VEPP-5 preinjector

Five Dimensional Rotating Black Hole in a Uniform Magnetic Field. The Gyromagnetic Ratio

In four dimensional general relativity, the fact that a Killing vector in a vacuum spacetime serves as a vector potential for a test Maxwell field provides one with an elegant way of describing the behaviour of electromagnetic fields near a rotating Kerr black hole immersed in a uniform magnetic field. We use a similar approach to examine the case of a five dimensional rotating black hole placed in a uniform magnetic field of configuration with bi-azimuthal symmetry, that is aligned with the angular momenta of the Myers-Perry spacetime. Assuming that the black hole may also possess a small electric charge we construct the 5-vector potential of the electromagnetic field in the Myers-Perry metric using its three commuting Killing vector fields. We show that, like its four dimensional counterparts, the five dimensional Myers-Perry black hole rotating in a uniform magnetic field produces an inductive potential difference between the event horizon and an infinitely distant surface. This potential difference is determined by a superposition of two independent Coulomb fields consistent with the two angular momenta of the black hole and two nonvanishing components of the magnetic field. We also show that a weakly charged rotating black hole in five dimensions possesses two independent magnetic dipole moments specified in terms of its electric charge, mass, and angular momentum parameters. We prove that a five dimensional weakly charged Myers-Perry black hole must have the value of the gyromagnetic ratio g=3.Comment: 23 pages, REVTEX, v2: Minor changes, v3: Minor change

A study of open strings ending on giant gravitons, spin chains and integrability

We systematically study the spectrum of open strings attached to half BPS giant gravitons in the N=4 SYM AdS/CFT setup. We find that some null trajectories along the giant graviton are actually null geodesics of AdS_5x S^5, so that we can study the problem in a plane wave limit setup. We also find the description of these states at weak 't Hooft coupling in the dual CFT. We show how the dual description is given by an open spin chain with variable number of sites. We analyze this system in detail and find numerical evidence for integrability. We also discover an interesting instability of long open strings in Ramond-Ramond backgrounds that is characterized by having a continuum spectrum of the string, which is separated from the ground state by a gap. This instability arises from accelerating the D-brane on which the strings end via the Ramond-Ramond field. From the integrable spin chain point of view, this instability prevents us from formulating the integrable structure in terms of a Bethe Ansatz construction.Comment: 38 pages+appendices, 9 figures. Uses JHEP3. v2: added reference

Fast Diffusion Process in Quenched hcp Dilute Solid 3^3He-4^4He Mixture

The study of phase structure of dilute $^3$He - $^4$He solid mixture of different quality is performed by spin echo NMR technique. The diffusion coefficient is determined for each coexistent phase. Two diffusion processes are observed in rapidly quenched (non-equilibrium) hcp samples: the first process has a diffusion coefficient corresponding to hcp phase, the second one has huge diffusion coefficient corresponding to liquid phase. That is evidence of liquid-like inclusions formation during fast crystal growing. It is established that these inclusions disappear in equilibrium crystals after careful annealing.Comment: 7 pages, 3 figures, QFS200

Inflationary Attractor from Tachyonic Matter

We study the complete evolution of a flat and homogeneous universe dominated by tachyonic matter. We demonstrate the attractor behaviour of the tachyonic inflation using the Hamilton-Jacobi formalism. We else obtain analytical approximations to the trajectories of the tachyon field in different regions. The numerical calculation shows that an initial non-vanishing momentum does not prevent the onset of inflation. The slow-rolling solution is an attractor.Comment: 4 pages, 2 figures, RevTe

Development of the BINP AMS complex at CCU SB RAS

The accelerator mass spectrometer created at BINP is installed at CCU “Geochronology of the cenazoic era” for sample dating by the ¹⁴С isotope. Present status of AMS complex and the results of experiments for radiocarbon concentration measurements in test samples are presented.Созданный в ИЯФ ускорительный масс-спектрометр установлен в ЦКП «Геохронология кайнозоя» для датирования образцов по изотопу ¹⁴С. Представлены текущее состояние комплекса УМС и результаты экспериментов по измерению концентрации радиоуглерода в тестовых образцах.Створений у ІЯФ прискорювальний мас-спектрометр встановлено в ЦКП «Геохронологія кайнозою» для датування зразків по ізотопу ¹⁴С. Представлено поточний стан комплексу УМЗ і результати експериментів з вимірювання концентрації радіовуглецю в тестових зразках

Small Black Holes on Cylinders

We find the metric of small black holes on cylinders, i.e. neutral and static black holes with a small mass in d-dimensional Minkowski-space times a circle. The metric is found using an ansatz for black holes on cylinders proposed in hep-th/0204047. We use the new metric to compute corrections to the thermodynamics which is seen to deviate from that of the (d+1)-dimensional Schwarzschild black hole. Moreover, we compute the leading correction to the relative binding energy which is found to be non-zero. We discuss the consequences of these results for the general understanding of black holes and we connect the results to the phase structure of black holes and strings on cylinders.Comment: 23 pages, 1 figure. v2: typos corrected, introduction expanded, v3: presentation of sections 2 and 3 reordered and improved, explanatory remarks added, refs adde

The S-matrix of the Faddeev-Reshetikhin Model, Diagonalizability and PT Symmetry

We study the question of diagonalizability of the Hamiltonian for the Faddeev-Reshetikhin (FR) model in the two particle sector. Although the two particle S-matrix element for the FR model, which may be relevant for the quantization of strings on $AdS_{5}\times S^{5}$, has been calculated recently using field theoretic methods, we find that the Hamiltonian for the system in this sector is not diagonalizable. We trace the difficulty to the fact that the interaction term in the Hamiltonian violating Lorentz invariance leads to discontinuity conditions (matching conditions) that cannot be satisfied. We determine the most general quartic interaction Hamiltonian that can be diagonalized. This includes the bosonic Thirring model as well as the bosonic chiral Gross-Neveu model which we find share the same S-matrix. We explain this by showing, through a Fierz transformation, that these two models are in fact equivalent. In addition, we find a general quartic interaction Hamiltonian, violating Lorentz invariance, that can be diagonalized with the same two particle S-matrix element as calculated by Klose and Zarembo for the FR model. This family of generalized interaction Hamiltonians is not Hermitian, but is $PT$ symmetric. We show that the wave functions for this system are also $PT$ symmetric. Thus, the theory is in a $PT$ unbroken phase which guarantees the reality of the energy spectrum as well as the unitarity of the S-matrix.Comment: 32 pages, 1 figure; references added, version published in JHE

Межэкспертная согласованность результатов МРТ диагностики патологии вращательной манжеты плечевого сустава

Background. The shoulder MRI is one of the main methods for the rotator cuff injuries diagnostics and determination of the further treatment tactics. The agreement in the MRI data interpretation among specialists regarding different types of shoulder ruptures is an integral part of diagnostic test validity evaluation. The purpose of this study was to assess the agreement in the MRI data interpretation in the patients with shoulder rotator cuff pathology among trauma surgeons, as well as between trauma surgeons and a radiologist. Materials and Methods. The study was a retrospective analysis of the MRI data and surgical reports regarding 57 patients with various shoulder pathologies undergone the shoulder MRI and arthroscopic shoulder revisions in the period from 2017 to 2019. There were 38 (67%) men and 19 (33%) women among the patients. The average age of the patients was 52.7±13.6 years. The sensitivity and specificity, as well as the shoulder MRI inter-rater reliability were assessed in the course of the study. Results. The rotator cuff pathology was revealed in 52 patients: supraspinatus tendon injury in 98% of cases, supraspinatus and infraspinatus tendon — in 26%, isolated subscapularis tendon injury — in 2%, supraspinatus and subscapularis tendon — in 39%. The maximal concordance in the MRI data interpretation was achieved in the patients with full-thickness supraspinatus tendon rupture, as well as with the supraspinatus tendon calcifications. However, significant disagreement was found between orthopedists with different work experience in determination of the presence and type of infraspinatus and subscapularis tendons pathology and supraspinatus tendon incomplete ruptures and tendinitis. Conclusion. The high agreement in the MRI data interpretation in determining the pathology of the shoulder rotator cuff among trauma surgeons, as well as between trauma surgeons and radiologists, was observed only regarding the supraspinatus tendon, calcifying tendonitis and full-thickness injury. The diagnosis of tendinitis and incomplete tendon rupture remains difficult. Their interpretation results vary greatly. It is also worth noting the heterogeneity of the results of diagnostics of the infraspinatus and subscapularis tendon pathology.Актуальность. МРТ плечевого сустава является одним из основных методов диагностики повреждений вращательной манжеты и определения дальнейшей тактики лечения. Согласованность результатов интерпретации МРТ между специалистами при различных вариантах разрывов плечевого сустава является неотъемлемой частью оценки эффективности диагностического теста. Цель — оценка согласованности интерпретации данных МРТ при патологии вращательной манжеты плечевого сустава между врачами-травматологами, а также между травматологами и рентгенологом. Материал и методы. Исследование представляет собой ретроспективный анализ результатов лучевых методов исследования и протоколов операций 57 пациентов с различными патологиями плечевого сустава, которым выполнялись МРТ плечевого сустава и артроскопическая ревизия плечевого сустава в период с 2017 по 2019 г. Среди обследованных было 38 (67%) мужчин и 19 (33%) женщин. Средний возраст пациентов составил 52,7±13,6 лет. В рамках работы была проведена оценка чувствительности и специфичности, а также межэкспертной надежности МРТ плечевого сустава. Результаты. У 52 пациентов была выявлена патология вращательной манжеты: в 98% случаев — повреждение сухожилия надостной мышцы, в 26% — сухожилия надостной и подостной мышц, в 2% — изолированное повреждение сухожилия подлопаточной мышцы и в 39% — повреждение сухожилий надостной и подлопаточной мышц. При анализе результатов максимальная согласованность интерпретации результатов МРТ была достигнута при определении полнослойного разрыва сухожилия надостной мышцы, а также кальцинатов сухожилия надостной мышцы. Однако были выявлены существенные разногласия между ортопедами с различным стажем работы в определении наличия и вида патологии сухожилий подостной и подлопаточной мышц, неполнослойных разрывов и тендиноза сухожилия надостной мышцы. Заключение. Высокая согласованность трактовки результатов МРТ в определении патологии вращательной манжеты плечевого сустава между травматологами, а также между травматологами и рентгенологами наблюдается только при оценке патологии сухожилия надостной мышцы, при кальцинирующем тендините и полнослойном повреждении. Диагностика тендинозов и неполнослойных разрывов остается затруднительной, и результаты интерпретации сильно разнятся. Стоит отметить также гетерогенность результатов диагностики патологии сухожилий подостной и подлопаточной мышц