470 research outputs found
Out-of-Time-Ordered Correlators in
In this note we continue analysing the non-equilibrium dynamics in the
orbifold conformal field theory. We compute the
out-of-time-ordered four-point correlators with twist operators. For rational
which is the square of the compactification radius, we find
that the correlators approach non-trivial constants at late time. For
they are expressed in terms of the modular matrices and for higher
orbifolds are functions of and . For irrational , we find a new
polynomial decay of the correlators that is a signature of an intermediate
regime between rational and chaotic models.Comment: 20 pages, 3 figure
Semiclassical analysis of the bifundamental QCD on with 't Hooft flux
We study the phase structure of bifundamental quantum chromodynamics
(QCD(BF)), which is the -dimensional gauge theory
coupled with the bifundamental fermion. Firstly, we refine constraints on its
phase diagram from 't Hooft anomalies and global inconsistencies, and we find
more severe constraints than those in previous literature about QCD(BF).
Secondly, we employ the recently-proposed semiclassical approach for confining
vacua to investigate this model concretely, and this is made possible via
anomaly-preserving compactification. For sufficiently small with
the 't Hooft flux, the dilute gas approximation of center vortices gives
reliable semiclassical computations, and we determine the phase diagram as a
function of the fermion mass , two strong scales ,
and two vacuum angles, . In particular, we find that the
QCD(BF) vacuum respects the exchange symmetry of two gauge
groups. Under the assumption of the adiabatic continuity, our result
successfully explains one of the conjectured phase diagrams in the previous
literature and also gives positive support for the nonperturbative validity of
the large- orbifold equivalence between QCD(BF) and
supersymmetric Yang-Mills theory. We also comment on problems of domain walls.Comment: 33 pages, 5 figures, small discussion adde
Degradable and Nanosegregated Elastomers with Multiblock Sequences of Biobased Aromatic Mesogens and Biofunctional Aliphatic Oligocarbonates
We have developed multiblock aromatic/aliphatic condensation polymers, comprising side-chain biofunctionalized aliphatic oligocarbonates and biobased aromatic ester triad mesogens up to 17 wt %. Nanosegregation of the aromatic mesogen-rich domains with diameters of approximately 10 nm from the soft aliphatic polymer matrix is suggested by atomic force microscopy. The polymers exhibit rubberlike properties, unlike the corresponding aliphatic polycarbonate forming viscous liquid. These properties support the interchain interactions between the aromatic mesogens, which can serve as physical cross-linking. The aromatic ester triad mesogens in the multiblock polymers significantly bolster the tolerance to organocatalytic hydrolysis and methanolysis of the polymer chains but are eventually degraded. The multiblock polymers show degradation behavior slightly faster than poly(L-lactide), whereas poly(ethylene terephthalate) remains intact under the same condition. The present study demonstrates the efficacy of aromatic ester triad mesogens incorporated into the sequences of biodegradable aliphatic polycarbonates to enhance their physical properties while retaining degradability
Mechanism of Nucleation Pathway Selection in Binary Lennard-Jones Solution: A Combined Study of Molecular Dynamics Simulation and Free Energy Analysis
The nucleation process, which is the initial step in particle synthesis, determines the properties of the resultant particles. Although recent studies have observed various nucleation pathways, the physical factors that determine these pathways have not been fully elucidated. Herein, we conducted molecular dynamics simulations in a binary Lennard-Jones system as a model solution and found that the nucleation pathway can be classified into four types depending on microscopic interactions. The key parameters are (1) the strength of the solute–solute interaction and (2) the difference between the strengths of the like-pair and unlike-pair interactions. The increment of the former alters the nucleation mechanism from a two-step to a one-step pathway, whereas that of the latter causes quick assembly of solutes. Moreover, we developed a thermodynamic model based on the formation of core-shell nuclei to calculate the free energy landscapes. Our model successfully described the pathway observed in the simulations and demonstrated that the two parameters, (1) and (2), define the degree of supercooling and supersaturation, respectively. Thus, our model interpreted the microscopic insights from a macroscopic point of view. Because the only inputs required for our model are the interaction parameters, our model can a priori predict the nucleation pathway
- …