9,194 research outputs found
Prolate-oblate asymmetric shape phase transition in the interacting boson model with SU (3) higher-order interactions
Prolate-oblate shape phase transition is an interesting topic in nuclear
structure, which is useful for understanding the intrinsic interactions between
nucleons. Recently, the interacting boson model with higher-order
interactions was proposed, in which the prolate shape and the oblate shape are
not described in a mirror symmetric way. This asymmetric description seems more
realistic. The level evolutions, values and other important indicators
showing the prolate-oblate asymmetric transitions are investigated in detail,
and realistic structure evolutions from Hf to Hg are compared.
A key finding is that, the average deformation of the prolate shape is nearly
twice the one of the oblate shape. These results, together with the successful
description of the anomaly in Os, Pt, the
-soft properties of Pt, Kr and the normal states of
Cd, support the validity of the new model.Comment: 16pages,19 figure
Emerging -softness in Pt in the SU3-IBM
Recently, it has been argued that a new -soft rotational spectrum
emerges in the interacting boson model with SU(3) higher-order interactions,
opening up new approaches to understand the -softness in realistic
nuclei. In a previous paper, -softness with degeneracy of the ground
and quasi- bands is observed, which displays a O(5) partial dynamical
symmetry. In this paper, another special point connected with the middle
degenerate point is discussed, which is found to be related with the properties
of Pt. This emergent -softness has also been shown to be
important for understanding the prolate-oblate asymmetric shape phase
transition. The low-lying spectra, values and quadrupole moments in
Pt are discussed showing that the new model can account for several
observed features
Splitting of surface defect partition functions and integrable systems
We study Bethe/gauge correspondence at the special locus of Coulomb moduli
where the integrable system exhibits the splitting of degenerate levels. For
this investigation, we consider the four-dimensional pure
supersymmetric gauge theory, with a half-BPS surface defect constructed
with the help of an orbifold or a degenerate gauge vertex. We show that the
non-perturbative Dyson-Schwinger equations imply the Schr\"odinger-type and the
Baxter-type differential equations satisfied by the respective surface defect
partition functions. At the special locus of Coulomb moduli the surface defect
partition function splits into parts. We recover the Bethe/gauge dictionary for
each summand.Comment: 34 pages, 2 figures; v2. published versio
Thoroughly Modeling Multi-domain Pre-trained Recommendation as Language
With the thriving of pre-trained language model (PLM) widely verified in
various of NLP tasks, pioneer efforts attempt to explore the possible
cooperation of the general textual information in PLM with the personalized
behavioral information in user historical behavior sequences to enhance
sequential recommendation (SR). However, despite the commonalities of input
format and task goal, there are huge gaps between the behavioral and textual
information, which obstruct thoroughly modeling SR as language modeling via
PLM. To bridge the gap, we propose a novel Unified pre-trained language model
enhanced sequential recommendation (UPSR), aiming to build a unified
pre-trained recommendation model for multi-domain recommendation tasks. We
formally design five key indicators, namely naturalness, domain consistency,
informativeness, noise & ambiguity, and text length, to guide the text-item
adaptation and behavior sequence-text sequence adaptation differently for
pre-training and fine-tuning stages, which are essential but under-explored by
previous works. In experiments, we conduct extensive evaluations on seven
datasets with both tuning and zero-shot settings and achieve the overall best
performance. Comprehensive model analyses also provide valuable insights for
behavior modeling via PLM, shedding light on large pre-trained recommendation
models. The source codes will be released in the future
Realization of broadband index-near-zero modes in nonreciprocal magneto-optical heterostructures
Epsilon-near-zero (ENZ) metamaterial with the relative permittivity
approaching zero has been a hot research subject in the past decades. The wave
in the ENZ region has infinite phase velocity (),
whereas it cannot efficiently travel into the other devices or air due to the
impedance mismatch or near-zero group velocity. In this paper, we demonstrate
that the tunable index-near-zero (INZ) modes with vanishing wavenumbers ()
and nonzero group velocities () can be achieved in
nonreciprocal magneto-optical systems. This kind of INZ modes has been
experimentally demonstrated in the photonic crystals at Dirac point frequencies
and that impedance-matching effect has been observed as well. Our theoretical
analysis reveals that the INZ modes exhibit tunability when changing the
parameter of the one-way (nonreciprocal) waveguides. Moreover, owing to the
zero-phase-shift characteristic and decreasing of the INZ modes,
several perfect optical buffers (POBs) are proposed in the microwave and
terahertz regimes. The theoretical results are further verified by the
numerical simulations performed by the finite element method. Our findings may
open the new avenues for research in the areas of ultra -strong or -fast
nonlinearity, perfect cloaking, high-resolution holographic imaging and
wireless communications
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