"Charged" Particle's Tunneling from Rotating Black Holes

The behavior of a scalar field theory near the event horizon in a rotating black hole background can be effectively described by a two dimensional field theory in a gauge field background. Based on this fact, we proposal that the quantum tunneling from rotating black hole can be treated as "charged" particle' s tunneling process in its effectively two dimensional metric. Using this viewpoint and considering the corresponding "gauge charge" conservation, we calculate the non-thermal tunneling rate of Kerr black hole and Myers-Perry black hole, and results are consistent with Parikh-Wilczek's original result for spherically symmetric black holes. Especially for Myers-Perry black hole which has multi-rotation parameters, our calculation fills in the gap existing in the literature applying Parikh-Wilczek's tunneling method to various types black holes. Our derivation further illuminates the essential role of effective gauge symmetry in Hawking radiation from rotating black holes.Comment: 15 pages, no figure; any comments are welcome

Primary lymphangiectasia of the gastrointestinal tract

Intestinal lymphangiectasia is a very rare pathology, characterized by the presence of enlarged lymphatic vessels in all layers of the intestinal wall and in the mesentery. As a result, "lymphatic lakes" are formed, through which lymph exudates into the lumen of the intestine. The main manifestation is hypoproteinemic edema. Diagnosis of the disease is based on laboratory-instrumental methods of investigation, including by determining in the stool α-1 antitrypsin as a screening test. Treatment includes: a diet rich in calcium, trace elements, be sure to use medicinal foods enriched with medium chain triglycerides, substitution and symptomatic therapy

How often does the Unruh-DeWitt detector click? Regularisation by a spatial profile

We analyse within first-order perturbation theory the instantaneous transition rate of an accelerated Unruh-DeWitt particle detector whose coupling to a massless scalar field on four-dimensional Minkowski space is regularised by a spatial profile. For the Lorentzian profile introduced by Schlicht, the zero size limit is computed explicitly and expressed as a manifestly finite integral formula that no longer involves regulators or limits. The same transition rate is obtained for an arbitrary profile of compact support under a modified definition of spatial smearing. Consequences for the asymptotic behaviour of the transition rate are discussed. A number of stationary and nonstationary trajectories are analysed, recovering in particular the Planckian spectrum for uniform acceleration.Comment: 30 pages, 1 figure. v3: Added references and minor clarification

Observer Dependent Horizon Temperatures: a Coordinate-Free Formulation of Hawking Radiation as Tunneling

We reformulate the Hamilton-Jacobi tunneling method for calculating Hawking radiation in static, spherically-symmetric spacetimes by explicitly incorporating a preferred family of frames. These frames correspond to a family of observers tied to a locally static timelike Killing vector of the spacetime. This formulation separates the role of the coordinates from the choice of vacuum and thus provides a coordinate-independent formulation of the tunneling method. In addition, it clarifies the nature of certain constants and their relation to these preferred observers in the calculation of horizon temperatures. We first use this formalism to obtain the expected temperature for a static observer at finite radius in the Schwarzschild spacetime. We then apply this formalism to the Schwarzschild-de Sitter spacetime, where there is no static observer with 4-velocity equal to the static timelike Killing vector. It is shown that a preferred static observer, one whose trajectory is geodesic, measures the lowest temperature from each horizon. Furthermore, this observer measures horizon temperatures corresponding to the well-known Bousso-Hawking normalization.Comment: 11 pages, 1 2-part figure, references added, appendix added, discussion streamline

Giant Anharmonic Phonon Scattering in PbTe

Understanding the microscopic processes affecting the bulk thermal conductivity is crucial to develop more efficient thermoelectric materials. PbTe is currently one of the leading thermoelectric materials, largely thanks to its low thermal conductivity. However, the origin of this low thermal conductivity in a simple rocksalt structure has so far been elusive. Using a combination of inelastic neutron scattering measurements and first-principles computations of the phonons, we identify a strong anharmonic coupling between the ferroelectric transverse optic (TO) mode and the longitudinal acoustic (LA) modes in PbTe. This interaction extends over a large portion of reciprocal space, and directly affects the heat-carrying LA phonons. The LA-TO anharmonic coupling is likely to play a central role in explaining the low thermal conductivity of PbTe. The present results provide a microscopic picture of why many good thermoelectric materials are found near a lattice instability of the ferroelectric type

Реализация фармацевтической разработки с применением многофакторного анализа многокритериальной оптимизации на примере этапа очистки гидросукцината олигогексаметиленгуанидина

Objectives. The study set out to use mathematical modeling, in particular the method of multifactorial analysis of multicriteria optimization (MAMO), in the development of a pharmaceutical product.Methods. After carrying out experimental tests based on the proposed algorithmic sequence, the obtained data were interpreted using MAMO.Results. The possibility of using MAMO to solve the applied problem of purifying oligohexamethyleneguanidine hydrosuccinate (OHMG-HS), considered as a pharmaceutical precursor for the creation of medicines, was demonstrated.Conclusions. The expediency of using the proposed algorithm as a tool for pharmaceutical development is substantiated by identifying dependencies of the influence of purification conditions on the final content of admixtures in the target product.Цели. Данное исследование посвящено использованию математического моделирования, в частности метода многофакторного анализа многокритериальной оптимизации (МАМО), в фармацевтической разработке.Методы. В ходе исследования была предложена алгоритмическая последовательность эксперимента и проведены необходимые испытания. Полученные данные были интерпретированы при помощи МАМО.Результаты. Изучена возможность применения МАМО для решения прикладной проблемы очистки гидросукцината олигогексаметиленгуанидина (ОГМГ-ГС), рассматриваемого в качестве фармацевтической субстанции для создания лекарственных средств.Выводы. Были выявлены зависимости влияния условий очистки на конечное содержание примесей в целевом продукте и доказана целесообразность использования предложенного алгоритма в качестве инструмента фармацевтической разработки

Применение микрофлюидного аппаратного оснащения в синтезе производных олигогексаметиленгуанидина

Objectives. To develop a method for the microfluidic synthesis of oligohexamethylene guanidine salts in a flow-type reactor and to evaluate its effectiveness in relation to the synthesis in a traditional capacitive reactor and compare the purities of products obtained by these methods.Methods. The synthesis of oligohexamethylene guanidine bihydrocarbonate (OHMG-BHC) was done using microfluidic hardware and the classical approach in volume. The purity and structure of the resulting product were confirmed by 13C NMR spectroscopy and high-performance liquid chromatography (HPLC).Results. The 13C NMR spectrum of OHMG-BHC in classical bulk synthesis demonstrates that the product is unbranched and contains additionally unidentifiable impurities, in contrast to the sample obtained by the microfluidic method. Furthermore, the HPLC analysis showed that the OHMG-BHC sample synthesized using microfluidic technology has a 1.5-fold lower content than the initial monomers.Conclusions. The advantage of synthesizing OHMG-BHC in a flow-type reactor compared to the traditional method of synthesis in volume is demonstrated since a product with a higher degree of purity is obtained.Цели. Разработать методику микрофлюидного синтеза солей олигогексаметиленгуанидина в реакторе проточного типа и оценить ее эффективность по сравнению с синтезом в классическом емкостном реакторе, а также сравнить чистоту продуктов, полученных данными методами.Методы. Синтез олигогексаметиленгуанидина дигидрокарбоната (ОГМГ-ДГК) проводили с применением микрофлюидного аппаратного оснащения и классическим методом в объеме. Подтверждение чистоты и структуры полученного продукта осуществляли с помощью 13C ЯМР спектроскопии и высокоэффективной жидкостной хроматографии (ВЭЖХ).Результаты. Спектр 13C ЯМР ОГМГ-ДГК при классическом синтезе в объеме демонстрирует, что продукт является неразветвленным и содержит дополнительно неидентифицируемые примеси в отличие от образца, полученного микрофлюидным способом. Анализ методом ВЭЖХ показал, что образец ОГМГ-ДГК, синтезированный с помощью микрофлюидной технологии, имеет в 1.5 раза более низкое содержание исходных мономеров.Выводы. Синтез ОГМГ-ДГК в проточном реакторе имеет преимущество по сравнению с классическим способом синтеза в объеме, поскольку выдает продукт с более высокой степенью чистоты

Black Hole Evaporation in a Noncommutative Charged Vaidya Model

The aim of this paper is to study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordstr$\ddot{o}$m-like solution of this model which leads to an exact $(t-r)$ dependent metric. The behavior of temporal component of this metric and the corresponding Hawking temperature is investigated. The results are shown in the form of graphs. Further, we examine the tunneling process of the charged massive particles through the quantum horizon. It is found that the tunneling amplitude is modified due to noncommutativity. Also, it turns out that black hole evaporates completely in the limits of large time and horizon radius. The effect of charge is to reduce the temperature from maximum value to zero. It is mentioned here that the final stage of black hole evaporation turns out to be a naked singularity.Comment: 25 pages, 36 figures, accepted for publication in J. Exp. Theor. Phy

Back reaction, emission spectrum and entropy spectroscopy

Recently, an interesting work, which reformulates the tunneling framework to directly produce the Hawking emission spectrum and entropy spectroscopy in the tunneling picture, has been received a broad attention. However, during the emission process, most related observations have not incorporated the effects of back reaction on the background spacetime, whose derivations are therefore not the desiring results for the real physical process. With this point as a central motivation, in this paper we suitably adapt the \emph{reformulated} tunneling framework so that it can well accommodate the effects of back reaction to produce the Hawking emission spectrum and entropy spectroscopy. Consequently, we interestingly find that, when back reaction is considered, the Parikh-Wilczek's outstanding observations that, an isolated radiating black hole has an unitary-evolving emission spectrum that is \emph{not} precisely thermal, but is related to the change of the Bekenstein-Hawking entropy, can also be reproduced in the reformulated tunneling framework, meanwhile the entropy spectrum has the same form as that without inclusion of back reaction, which demonstrates the entropy quantum is \emph{independent} of the effects of back reaction. As our final analysis, we concentrate on the issues of the black hole information, but \emph{unfortunately} find that, even including the effects of back reaction and higher-order quantum corrections, such tunneling formalism can still not provide a mechanism for preserving the black hole information.Comment: 16 pages, no figure, use JHEP3.cls. to be published in JHE