274 research outputs found
Semicontinuity for representations of one-dimensional Cohen-Macaulay rings
We show that the number of parameters for CM-modules of prescribed rank is
semi-continuous in families of CM rings of Krull dimension 1. This transfers a
result of Knoerrer from the commutative to the not necessarily commutative
case. For this purpose we introduce the notion of ``dense subrings'' which
seems rather technical but, nevertheless, useful. It enables the construction
of ``almost versal'' families of modules for a given algebra and the definition
of the ``number of parameters''. The semi--continuity implies, in particular,
that the set of so-called ``wild algebras'' in any family is a countable union
of closed subsets. A very exciting problem is whether it is actually closed,
hence whether the set of tame algebras is open. However, together with the
results of a former paper of the authors the semi-continuity implies that tame
is indeed an open property for curve singularities (commutative CM rings). An
analogous procedure leads to the semicontinuity of the number of parameters in
other cases, like representations of finite dimensional algebras or finite
dimensional bimodules.Comment: LaTeX2
Hypernuclear event detection in the nuclear emulsion with Monte Carlo simulation and machine learning
This study developed a novel method for detecting hypernuclear events
recorded in nuclear emulsion sheets using machine learning techniques. The
artificial neural network-based object detection model was trained on surrogate
images created through Monte Carlo simulations and image-style transformations
using generative adversarial networks. The performance of the proposed model
was evaluated using -decay events obtained from the J-PARC E07 emulsion
data. The model achieved approximately twice the detection efficiency of
conventional image processing and reduced the time spent on manual visual
inspection by approximately 1/17. The established method was successfully
applied to the detection of hypernuclear events. This approach is a
state-of-the-art tool for discovering rare events recorded in nuclear emulsion
sheets without any real data for training.Comment: 32 pages, 13 figure
Multi-Scalar-Singlet Extension of the Standard Model - the Case for Dark Matter and an Invisible Higgs Boson
We consider a simple extension of the Standard Model by the addition of N
real scalar gauge singlets \vp that are candidates for Dark Matter. By
collecting theoretical and experimental constraints we determine the space of
allowed parameters of the model. The possibility of ameliorating the little
hierarchy problem within the multi-singlet model is discussed. The
Spergel-Steinhardt solution of the Dark Matter density cusp problem is
revisited. It is shown that fitting the recent CRESST-II data for Dark Matter
nucleus scattering implies that the standard Higgs boson decays predominantly
into pairs of Dark Matter scalars. It that case discovery of the Higgs boson at
LHC and Tevatron is impossible. The most likely mass of the dark scalars is in
the range 15 GeV \lsim \mvp \lsim 50 GeV with BR(h \to \vp\vp) up to 96%.Comment: 18 pages, 15 figure
Mutation in triangulated categories and rigid Cohen-Macaulay modules
We introduce the notion of mutation of -cluster tilting subcategories in a
triangulated category with Auslander-Reiten-Serre duality. Using this idea, we
are able to obtain the complete classifications of rigid Cohen-Macaulay modules
over certain Veronese subrings.Comment: 52 pages. To appear in Invent. Mat
Direct detection of Higgs-portal dark matter at the LHC
We consider the process in which a Higgs particle is produced in association
with jets and show that monojet searches at the LHC already provide interesting
constraints on the invisible decays of a 125 GeV Higgs boson. Using the
existing monojet searches performed by CMS and ATLAS, we show the 95%
confidence level limit on the invisible Higgs decay rate is of the order of the
total Higgs production rate in the Standard Model. This limit could be
significantly improved when more data at higher center of mass energies are
collected, provided systematic errors on the Standard Model contribution to the
monojet background can be reduced. We also compare these direct constraints on
the invisible rate with indirect ones based on measuring the Higgs rates in
visible channels. In the context of Higgs portal models of dark matter, we then
discuss how the LHC limits on the invisible Higgs branching fraction impose
strong constraints on the dark matter scattering cross section on nucleons
probed in direct detection experiments.Comment: 6 pages, 3 figures; v2: references added; v3: monojet and Higgs data
updated, version published in EPJ
Cycle-finite module categories
We describe the structure of module categories of finite dimensional algebras
over an algebraically closed field for which the cycles of nonzero
nonisomorphisms between indecomposable finite dimensional modules are finite
(do not belong to the infinite Jacobson radical of the module category).
Moreover, geometric and homological properties of these module categories are
exhibited
The Universal One-Loop Effective Action
We present the universal one-loop effective action for all operators of
dimension up to six obtained by integrating out massive, non-degenerate
multiplets. Our general expression may be applied to loops of heavy fermions or
bosons, and has been checked against partial results available in the
literature. The broad applicability of this approach simplifies one-loop
matching from an ultraviolet model to a lower-energy effective field theory
(EFT), a procedure which is now reduced to the evaluation of a combination of
matrices in our universal expression, without any loop integrals to evaluate.
We illustrate the relationship of our results to the Standard Model (SM) EFT,
using as an example the supersymmetric stop and sbottom squark Lagrangian and
extracting from our universal expression the Wilson coefficients of
dimension-six operators composed of SM fields.Comment: 30 pages, v2 contains additional comments and corrects typos, version
accepted for publication in JHE
Constraining parameter space in type-II two-Higgs doublet model in light of a 126 GeV Higgs boson
We explore the implications of a 126 GeV Higgs boson indicated by the recent
LHC results for two-Higgs doublet model (2HDM). Identifying the 126 GeV Higgs
boson as either the lighter or heavier of CP even neutral Higgs bosons in 2HDM,
we examine how the masses of Higgs fields and mixing parameters can be
constrained by the theoretical conditions and experimental constraints. The
theoretical conditions taken into account are the vacuum stability,
perturbativity and unitarity required to be satisfied up to a cut-off scale. We
also show how bounds on the masses of Higgs bosons and mixing parameters depend
on the cut-off scale. In addition, we investigate whether the allowed regions
of parameter space can accommodate particularly the enhanced di-photon signals,
ZZ* and WW* decay modes of the Higgs boson, and examine the prediction of the
signal strength of Z{\gamma} decay mode for the allowed regions of the
parameter space.Comment: To be published in JHEP, 20 pages, 11 figures, Figures and results
are updated for the recent LHC result
Судебные экспертизы, назначаемые при расследовании преступлений, совершенных против журналистов
Forensic examinations appointed at the investigation of crimes committed
against journalists / Drozd Valentyna, Luchenko Dmytro, Ablamskiy Sergii, Vatras Volodymyr // Amazonia Investiga. – 2019. – Vol 8, No 24. – P. 130-137.Drozd, V., et al. "Forensic Examinations Appointed at the Investigation of Crimes Committed against Journalists." Amazonia Investiga 8.24 (2019): 130-37. Print.Проаналізовано особливості застосування спеціальних знань, зокрема, щодо призначення судових експертиз при розслідуванні злочинів, скоєних проти журналістів. З урахуванням аналізу наукової літератури, а також наявної практики розслідування кримінальних проваджень зазначеної категорії надано характеристику таких видів судових експертиз, як товарознавчої, судово-медичної, компьютернотехніческой, фоноскопічної, молекулярно-генетичної, комплексної судової експертизи, запахових слідів людини, дактилоскопічної. Звернуто увагу, що кількість і види судових експертиз призначаються в залежності від встановлених обставин, первинної кваліфікації скоєного злочину, етапу розслідування. Метою статті було визначення переліку судових експертиз, що призначаються при розслідуванні
злочинів, скоєних проти журналістів. Для досягнення поставленої мети використано загальнонаукові та
спеціальні методи пізнання. За допомогою методу юридичного аналізу визначено, що призначення судових експертиз у кримінальних виробництвах, що розслідуються по
фактом вчинення злочину проти журналіста, має важливу роль при встановленні обставин, що підлягають доказуванню (наприклад, таких як розмір заподіяної шкоди; тяжкість і характер тілесних ушкоджень та ін.). Сравнітельноправовой метод застосовувався в ході вивчення
практики Європейського суду з прав людини. Статистичний метод покладено в основу обробки статистичних даних, матеріалів слідчої та судової практики. За результатами проведеного дослідження акцентовано увагу, що при призначенні того чи іншого виду судової експертизи слідчому необхідно вірно визначити коло завдань, які ставляться експертові на дозвіл. Також слідчому необхідно скористатися методичними рекомендаціями, які сьогодні напрацьовані практикою і викладені в Науково-методичних рекомендаціях з питань підготовки та призначення судових експертиз та експертних досліджень.The specifics of the implementation of special knowledge have been analyzed, in particular regarding the appointment of forensic examinations while the investigation of crimes committed against journalists. Taking into account the analysis of scientific literature, as well as existing practice regarding the investigation of criminal proceedings of this category, the author has presented a characteristic of typical types of forensic examinations. In particular, special attention has been paid to such types as merchandising, forensic and medical, computer and technological, phonoscopic, molecular and genetic, integrated forensic examinations, human odor traces, fingerprints, etc. It has been emphasized that the number and types of forensic examinations are assigned depending on the established circumstances. The purpose of the paper is to identify forensic examinations that are assigned to investigate crimes committed against journalists. To achieve this objective, the author has used general scientific and special methods of cognition. Thus, using the method of legal analysis, the author has determined that the appointment and conduction of forensic examinations in criminal proceedings, investigated on the fact of committing a crime against a journalist, has an important role in establishing the circumstances to be proved (the type and size of the caused damage; the severity and nature of the bodily harm, etc.). The comparative and legal method has been used in the course of studying the practice of the European Court of Human Rights and analyzing the criminal and procedural legislation of other countries. The statistical method is the basis for processing statistical data, materials of investigative and court practice. Therefore, attention has been paid to the fact that whole assigning a particular type of forensic examination, an investigator has to correctly determine the range of tasks that are put to an expert. An investigator must also use the methodological recommendations that have been developed by practice and set out in the Scientific and Methodological Recommendations on the Preparation and Appointment of Forensic Examinations and Expert Studies.Проанализированы особенности применения
специальных знаний, в частности,
относительно назначения судебных
экспертиз при расследовании преступлений,
совершенных против журналистов. С учетом
анализа научной литературы, а также
имеющейся практики расследования
уголовных производств указанной категории
предоставлена характеристика таких видов
судебных экспертиз, как товароведческой,
судебно-медицинской, компьютернотехнической, фоноскопической,
молекулярно-генетической, комплексной
судебной экспертизе, запаховых следов
человека, дактилоскопической. Обращено
внимание, что количество и виды судебных
экспертиз назначаются в зависимости от
установленных обстоятельств, первичной
квалификации совершенного преступления,
этапа расследования. Целью статьи явилось
определение перечня судебных экспертиз,
назначаемых при расследовании
преступлений, совершенных против
журналистов. Для достижения поставленной цели использованы общенаучные и
специальные методы познания. С помощью
метода юридического анализа определено,
что назначение судебных экспертиз в
уголовных производствах, расследуемых по
факту совершения преступлению против
журналиста, имеет важную роль при
установлении обстоятельств, подлежащих
доказыванию (например, таких как размер
причиненного ущерба; тяжесть и характер
телесных повреждений и др.). Сравнительноправовой метод применялся в ходе изучения
практики Европейского суда по правам
человека. Статистический метод положен в
основу обработки статистических данных,
материалов следственной и судебной
практики. За результатами проведенного
исследования акцентировано внимание, что
при назначении того или иного вида судебной
экспертизы следователю необходимо верно
определить круг задач, которые ставятся
эксперту на разрешение. Также следователю
необходимо воспользоваться методическими
рекомендациями, которые сегодня
наработаны практикой и изложены в Научно-методических рекомендациях по вопросам подготовки и назначения судебных экспертиз
и экспертных исследований
- …