463 research outputs found
R-local Delaunay inhibition model
Let us consider the local specification system of Gibbs point process with
inhib ition pairwise interaction acting on some Delaunay subgraph specifically
not con taining the edges of Delaunay triangles with circumscribed circle of
radius grea ter than some fixed positive real value . Even if we think that
there exists at least a stationary Gibbs state associated to such system, we do
not know yet how to prove it mainly due to some uncontrolled "negative"
contribution in the expression of the local energy needed to insert any number
of points in some large enough empty region of the space. This is solved by
introducing some subgraph, called the -local Delaunay graph, which is a
slight but tailored modification of the previous one. This kind of model does
not inherit the local stability property but satisfies s ome new extension
called -local stability. This weakened property combined with the local
property provides the existence o f Gibbs state.Comment: soumis \`{a} Journal of Statistical Physics 27 page
Bell's Jump Process in Discrete Time
The jump process introduced by J. S. Bell in 1986, for defining a quantum
field theory without observers, presupposes that space is discrete whereas time
is continuous. In this letter, our interest is to find an analogous process in
discrete time. We argue that a genuine analog does not exist, but provide
examples of processes in discrete time that could be used as a replacement.Comment: 7 pages LaTeX, no figure
“A Garden of Forking Paths”: Reimagining Dreiser (Dreiser’s Path: A View With a Modern Lens. Edited by Irina V. Morozova. Moscow: RSUH Publ., 2023. 206 p.)
The review focuses on the collective monograph Dreiser’s Path: A View with a Modern Lens (2023). The scholarly work reevaluates Dreiser's significance as a classic of American literature and offers a contemporary perspective on his legacy through the lens of modern methodologies such as critical race theory, postcolonial theory, gender theory, etc. The attention of prominent researchers in American literature and culture from Russia, the USA, Canada, and the UK is drawn to Dreiser's contradictory and hermetic view of society and its artistic projection. The monograph reevaluates Dreiser's creative legacy, considering both major and well-known works as well as minor forms. The researchers featured in the monograph highlight the reasons why certain laws operate in Dreiser's artistic world, align Dreiser's value system with the social norms prevailing during his time, typologize the components of Dreiser's texts, and theorize them using contemporary methodological tools. They also juxtapose Dreiser's texts with other artifacts of American culture and demonstrate the evolution of Dreiser's perception from the times of the USSR to the present day. The monograph was conceived in 2021 as a special tribute to Theodore Dreiser to mark his 150 anniversary
Phase Transition in Ferromagnetic Ising Models with Non-Uniform External Magnetic Fields
In this article we study the phase transition phenomenon for the Ising model
under the action of a non-uniform external magnetic field. We show that the
Ising model on the hypercubic lattice with a summable magnetic field has a
first-order phase transition and, for any positive (resp. negative) and bounded
magnetic field, the model does not present the phase transition phenomenon
whenever , where is the external
magnetic field.Comment: 11 pages. Published in Journal of Statistical Physics - 201
Universal Probability Distribution for the Wave Function of a Quantum System Entangled with Its Environment
A quantum system (with Hilbert space ) entangled with its
environment (with Hilbert space ) is usually not attributed a
wave function but only a reduced density matrix . Nevertheless, there
is a precise way of attributing to it a random wave function , called
its conditional wave function, whose probability distribution depends
on the entangled wave function in
the Hilbert space of system and environment together. It also depends on a
choice of orthonormal basis of but in relevant cases, as we
show, not very much. We prove several universality (or typicality) results
about , e.g., that if the environment is sufficiently large then for
every orthonormal basis of , most entangled states with
given reduced density matrix are such that is close to one of
the so-called GAP (Gaussian adjusted projected) measures, . We
also show that, for most entangled states from a microcanonical subspace
(spanned by the eigenvectors of the Hamiltonian with energies in a narrow
interval ) and most orthonormal bases of ,
is close to with the
normalized projection to the microcanonical subspace. In particular, if the
coupling between the system and the environment is weak, then is close
to with the canonical density matrix on
at inverse temperature . This provides the
mathematical justification of our claim in [J. Statist. Phys. 125:1193 (2006),
http://arxiv.org/abs/quant-ph/0309021] that measures describe the thermal
equilibrium distribution of the wave function.Comment: 27 pages LaTeX, no figures; v2 major revision with simpler proof
Concentration inequalities for random fields via coupling
We present a new and simple approach to concentration inequalities for
functions around their expectation with respect to non-product measures, i.e.,
for dependent random variables. Our method is based on coupling ideas and does
not use information inequalities. When one has a uniform control on the
coupling, this leads to exponential concentration inequalities. When such a
uniform control is no more possible, this leads to polynomial or
stretched-exponential concentration inequalities. Our abstract results apply to
Gibbs random fields, in particular to the low-temperature Ising model which is
a concrete example of non-uniformity of the coupling.Comment: New corrected version; 22 pages; 1 figure; New result added:
stretched-exponential inequalit
Interactive Robot for Playing Russian Checkers
Human\u2013robot interaction in board games is a rapidly developing field of robotics. This paper presents a robot capable of playing Russian checkers designed for entertaining, training, and research purposes. Its control program is based on a novel unsupervised self-learning algorithm inspired by AlphaZero and represents the first successful attempt of using this approach in the checkers game. The main engineering challenge in mechanics is to develop a board state acquisition system non-sensitive to lighting conditions, which is achieved by rejecting computer vision and utilizing magnetic sensors instead. An original robot face is designed to endow the robot an ability to express its attributed emotional state. Testing the robot at open-air multiday exhibitions shows the robustness of the design to difficult exploitation conditions and the high interest of visitors to the robot
siRNAdb: a database of siRNA sequences
Short interfering RNAs (siRNAs) are a popular method for gene-knockdown, acting by degrading the target mRNA. Before performing experiments it is invaluable to locate and evaluate previous knockdown experiments for the gene of interest. The siRNA database provides a gene-centric view of siRNA experimental data, including siRNAs of known efficacy and siRNAs predicted to be of high efficacy by a combination of methods. Linked to these sequences is information such as siRNA thermodynamic properties and the potential for sequence-specific off-target effects. The database enables the user to evaluate an siRNA's potential for inhibition and non-specific effects. The database is available at http://siRNA.cgb.ki.se
The meaning of the 'impact factor' in the case of an open-access journal
The dominant model of journal evaluation emerged at the time when there were no open-access journals, and nobody has assessed yet whether this model is able to cope with this modern reality. This commentary attempts to fill the gaps in the common understanding of the role that 'impact factor' should play in evaluation of open-access journals
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