Dressing a black hole with non-minimally coupled scalar field hair

We investigate the possibility of dressing a four-dimensional black hole with classical scalar field hair which is non-minimally coupled to the space-time curvature. Our model includes a cosmological constant but no self-interaction potential for the scalar field. We are able to rule out black hole hair except when the cosmological constant is negative and the constant governing the coupling to the Ricci scalar curvature is positive. In this case, non-trivial hairy black hole solutions exist, at least some of which are linearly stable. However, when the coupling constant becomes too large, the black hole hair becomes unstable.Comment: 17 pages, 7 figures, uses iopart.cls. Minor changes, accepted for publication in Classical and Quantum Gravit

Lysosomal acid lipase deficiency – an underestimated cause of hypercholesterolemia in children

Lysosomal acid lipase deficiency (LAL-D) is a rare, progressive, autosomal recessive disease, which develops due to impaired degradation and subsequent intra-lysosomal accumulation of triglycerides and cholesterol esters causing dyslipidemia. The clinical manifestations of the disease presumably depend on the residual activity of the enzyme, lysosomal acid lipase. A profound deficiency of the enzyme known as Wolman’s disease has an onset in the first 6 months of life. The disease reveals itself by dyspeptic disorders in the form of vomiting and diarrhea, lack of weight gain, hepatosplenomegaly, and adrenal calcification. If the Wolman’s disease is not treated, children die within the first 6 months as a result of exhaustion caused by malabsorption syndrome combined with progressive deterioration of liver and adrenal glands. Partial deficiency of lysosomal acid lipase manifests itself at a later age and is called cholesterol ester storage disease. Its clinical presentations include hepatosplenomegaly, elevated transaminases, hypercholesterolemia, and, in some cases, hypertriglyceridemia. Liver failure is the main cause of death in the natural course of cholesterol ester storage disease. Delayed diagnosis of the disease leads to its progression causing irreversible liver damage. The implementation of mass screening programs with the determination of cholesterol levels in childhood is critical to identifying asymptomatic patients.The article presents a clinical case of a patient aged 3 years. The molecular genetic testing showed a mutation in exon 8 of the LIPA gene: NM_000235.3:c.894G>A synonymous variant in the homozygous state. It was also found that both parents of the girl had this type of mutation in the heterozygous state. The patient was prescribed sebelipase alfa in a dose of 1 mg/kg once every 14 days. The treatment was well tolerated. Due to the early verification of the diagnosis and timely pathogenetic therapy, the prognosis of the course of LAL-D, the duration and quality of life of the child were considered to be favourable.Raising the awareness of doctors along with the introduction of effective screening programs for the timely detection of dyslipidemia in children contributes to timely diagnosis and early initiation of pathogenetic therapy, which can increase the life expectancy of patients with lysosomal acid lipase deficiency and improve their quality of life

Distance Properties of Short LDPC Codes and their Impact on the BP, ML and Near-ML Decoding Performance

Parameters of LDPC codes, such as minimum distance, stopping distance, stopping redundancy, girth of the Tanner graph, and their influence on the frame error rate performance of the BP, ML and near-ML decoding over a BEC and an AWGN channel are studied. Both random and structured LDPC codes are considered. In particular, the BP decoding is applied to the code parity-check matrices with an increasing number of redundant rows, and the convergence of the performance to that of the ML decoding is analyzed. A comparison of the simulated BP, ML, and near-ML performance with the improved theoretical bounds on the error probability based on the exact weight spectrum coefficients and the exact stopping size spectrum coefficients is presented. It is observed that decoding performance very close to the ML decoding performance can be achieved with a relatively small number of redundant rows for some codes, for both the BEC and the AWGN channels

Quasi-normal Modes of Electromagnetic Perturbations of Four-Dimensional Topological Black Holes with Scalar Hair

We study the perturbative behaviour of topological black holes with scalar hair. We calculate both analytically and numerically the quasi-normal modes of the electromagnetic perturbations. In the case of small black holes we find evidence of a second-order phase transition of a topological black hole to a hairy configuration.Comment: v2: 19 pages, 2 figures, added references, improved discussion, to appear in JHE

Quasi-normal modes of the scalar hairy black hole

We calculate QNMs of the scalar hairy black hole in the AdS background using Horowitz-Hubeny method for the potential that is not known in analytical form. For some black hole parameters we found pure imaginary frequencies. Increasing of the scalar field mass does not cause the imaginary part to vanish, it reaches some minimum and then increases, thus in the case under consideration the infinitely long living modes (quasi-resonances) do not appear.Comment: 17 pages, 17 figures, LaTe

"No-Scalar-Hair" Theorems for Nonminimally Coupled Fields with Quartic Self-Interaction

Self-gravitating scalar fields with nonminimal coupling to gravity and having a quartic self-interaction are considered in the domain of outer communications of a static black hole. It is shown that there is no value of the nonminimal coupling parameter $\zeta$ for which nontrivial static black hole solutions exist. This result establishes the correctness of Bekenstein ``no-scalar-hair'' conjecture for quartic self-interactions.Comment: 8 pages, RevTeX

On Black Hole Scalar Hair in Asymptotically Anti de Sitter Spacetimes

The unexpected discovery of hairy black hole solutions in theories with scalar fields simply by considering asymptotically Anti de-Sitter, rather than asymptotically flat, boundary conditions is analyzed in a way that exhibits in a clear manner the differences between the two situations. It is shown that the trivial Schwarzschild Anti de Sitter becomes unstable in some of these situations, and the possible relevance of this fact for the ADS/CFT conjecture is pointed out.Comment: 12 pages. Published versio

Оценка влияния комплекса биопрепаратов на рост, развитие и урожайность огурца в условиях светокультуры

The ecologization of protected soil is currently one of the most important tasks of agricultural production, in this regard, for the vegetable growing of protected soil, the introduction of effective microorganisms into the substrate when growing plants in low-volume technology is of great interest. Biologics can enhance metabolic processes in the nutrient substrate and plants, plant resistance to adverse environmental conditions, increase plant productivity and improve product quality. Therefore, the purpose of our work is to analyze the effect of a complex of biological products on the agrobiological parameters of cucumber hybrids Mewa F1 and Valigora F1 on the 39, 67, 95 and 123 day of cultivation from the appearance of mass shoots. The research was carried out in conditions of high industrial greenhouses of the "Venlo" type, in the winter-spring turns of 2021 and 2022. The preparations were introduced into the tank mixture and fed to the plants through a drip irrigation system. Measurements of economically valuable indicators were noted weekly. Descriptive statistics and ANOVA methods were used for statistical data analysis.Results. When using biological products, a positive effect was noted on the growth and development of cucumber plants, as well as on the increase in leaf plate and leaf surface area (LAI). The dates of the onset of single and mass flowering of plants and single fruiting occurred earlier when using a complex of biological preparations for 1-5 days. When assessing the effect of the complex of biological products on the development of the photosynthetic apparatus, the positive effect of biological products on the area and index of the leaf surface on the 39, 67 and 95 days of cultivation was established. In addition, a significant effect of the complex on the increase in yield per m2 per turnover was revealed. In the conducted studies, the increase in yield was due to an increase in the weight and diameter of fruits. The total height of the plants and the weekly growth of the complex of drugs practically did not affect. A comparative analysis of the growth processes and yield of cucumber hybrids Mewa F1 and Valigora F1 when applying root fertilizing with a complex of biological preparations showed great effectiveness from their use.Экологизация защищенного грунта, на данный момент – одна из важнейших задач сельскохозяйственного производства, в связи с этим, для овощеводства защищенного грунта большой интерес представляет внесение в субстрат при выращивании растений в малообъемной технологии эффективных микроорганизмов. Биопрепараты способны усилить обменные процессы в питательном субстрате и растениях, устойчивость растений к неблагоприятным условиям среды, повысить продуктивность растений и улучшить качество продукции. Поэтому целью нашей работы является анализ влияния комплекса биопрепаратов на агробиологические показатели гибридов огурца Mewa F1 и Valigora F1 на 39, 67, 95 и 123 сутки выращивания от появления массовых всходов. Исследования проводили в условиях высоких промышленных теплиц типа «Venlo», в зимне-весенних оборотах 2021 и 2022 годов. Препараты вносили в баковую смесь и подавали к растениям через систему капельного полива. Измерения хозяйственно ценных показателей отмечали еженедельно. Для статистического анализа данных использовали методы описательных статистик и ANOVA.Результаты. При применении биопрепаратов было отмечено положительное воздействие на рост и развитие растений огурца, а также на увеличение листовой пластинки и площади листовой поверхности (ИПЛ). Даты наступления единичного и массового цветения растений и единичного плодоношения наступали раньше при применении комплекса биопрепаратов на 1-5 суток. При оценке влияния комплекса биопрепаратов на развитие фотосинтетического аппарата установлено положительное влияние биопрепаратов на площадь и индекс листовой поверхности на 39, 67 и 95-е сутки выращивания. Кроме того, выявлено достоверное влияние комплекса на увеличение урожайности с м2 за оборот. В проведенных исследования увеличение урожайности происходило за счет увеличения массы и диаметра плодов. На общую высоту растений и недельный прирост комплекс препаратов практически не повлиял. Сравнительный анализ ростовых процессов и урожайности гибридов огурца Mewa F1 и Valigora F1 при применении корневых подкормок комплексом биопрепаратов показал большую эффективность от их применения

A New Class of Exact Hairy Black Hole Solutions

We present a new class of black hole solutions with minimally coupled scalar field in the presence of a negative cosmological constant. We consider a one-parameter family of self-interaction potentials parametrized by a dimensionless parameter $g$. When $g=0$, we recover the conformally invariant solution of the Martinez-Troncoso-Zanelli (MTZ) black hole. A non-vanishing $g$ signals the departure from conformal invariance. All solutions are perturbatively stable for negative black hole mass and they may develop instabilities for positive mass. Thermodynamically, there is a critical temperature at vanishing black hole mass, where a higher-order phase transition occurs, as in the case of the MTZ black hole. Additionally, we obtain a branch of hairy solutions which undergo a first-order phase transition at a second critical temperature which depends on $g$ and it is higher than the MTZ critical temperature. As $g\to 0$, this second critical temperature diverges.Comment: 18 pages, 6 figures, minor changes, references added, published versio