Loop Corrections in Double Field Theory: Non-trivial Dilaton Potentials

It is believed that the invariance of the generalised diffeomorphisms prevents any non-trivial dilaton potential from double field theory. It is therefore difficult to include loop corrections in the formalism. We show that by redefining a non-local dilaton field, under strong constraint which is necessary to preserve the gauge invariance of double field theory, the theory does permit non-constant dilaton potentials and loop corrections. If the fields have dependence on only one single coordinate, the non-local dilaton is identical to the ordinary one with an additive constant.Comment: V3, 11 pages, references added, typos corrected, version to appear in JHE

Fabrication and Characterization of Hybrid Nanocomposites by Matrix Assisted Pulsed Laser Evaporation

Different methods have been applied to deposit hybrid nanocomposites which can be applied in various fields due to their light weight and multifunctional properties. Here, matrix assisted pulsed laser evaporation (MAPLE) equipment with 532 nm Nd:YAG laser is applied to fabricate three types of hybrid nanocomposites on different substrates. Chemical synthesized FeCo nanoparticles were deposited on graphene sheets by MAPLE technique (laser fluence: 300 mJ/cm2). The effects of deposition time (t) on particle amount, shape and size have been investigated. Yttrium barium copper oxide (YBCO) materials are one type of high-temperature superconductive materials and could be applied in transportation. To fabricate superconductive materials/graphene hybrid nanocomposites, YBCO nanoparticles were deposited on graphene sheets by MAPLE techniques with a laser fluence at 150 mJ/cm2. The microstructures in terms of particle size, size distribution, and particle shape are studied as functions of the deposition time (t). In addition, up-conversion nanoparticles (NaGdF4: Yb3+, Er3+) which are able to be excited by low energy photons (λex = 980 nm) and emit high energy photons were deposited through MAPLE technique. Results indicate that 2 hours’ deposition can result in high-quality samples in terms of particle size and particle amount. No toxic effect is imposed on the cells by the deposited up-conversion nanoparticles with/without protein modification. Our results indicate that the MAPLE deposition technique demonstrates the good versatility of depositing different nanoparticles and preserving their chemical composition

Impact of top-Higgs couplings on di-Higgs production at future colliders

Measuring the Higgs-self coupling is one of the most crucial goals of the future colliders, such as the LHC Run-II and the ILC-based photon collider. Since the new physics can affects the di-Higgs production not only from the Higgs self-coupling but also from the top-Higgs coupling, we investigate the di-Higgs production in the presence of the non-standard top-Higgs coupling at the LHC and ILC-based photon collider given the recent Higgs data. Due to the changed interference behaviors of the top quark loops with itself or $W$ boson loops, we find that the cross section of di-Higgs production at the LHC-14 TeV and ILC-500 GeV can be respectively enhanced up to nearly 3 and 2 times the SM predictions within 2$\sigma$ Higgs data allowed parameter region.Comment: 16 pages, references and discussions added, accepted by JHE

Synthetic gauge fields enable high-order topology on Brillouin real projective plane

The topology of the Brillouin zone, foundational in topological physics, is always assumed to be a torus. We theoretically report the construction of Brillouin real projective plane ($\mathrm{RP}^2$) and the appearance of quadrupole insulating phase, which are enabled by momentum-space nonsymmorphic symmetries stemming from $\mathbb{Z}_2$ synthetic gauge fields. We show that the momentum-space nonsymmorphic symmetries quantize bulk polarization and Wannier-sector polarization nonlocally across different momenta, resulting in quantized corner charges and an isotropic binary bulk quadrupole phase diagram, where the phase transition is triggered by a bulk energy gap closing. Under open boundary conditions, the nontrivial bulk quadrupole phase manifests either trivial or nontrivial edge polarization, resulting from the violation of momentum-space nonsymmorphic symmetries under lattice termination. We present a concrete design for the $\mathrm{RP}^2$ quadrupole insulator based on acoustic resonator arrays and discuss its feasibility in optics, mechanics, and electrical circuits. Our results show that deforming the Brillouin manifold creates opportunities for realizing high-order band topology.Comment: 5 pages,5 figure

Simple Hardware-Efficient PCFGs with Independent Left and Right Productions

Scaling dense PCFGs to thousands of nonterminals via a low-rank parameterization of the rule probability tensor has been shown to be beneficial for unsupervised parsing. However, PCFGs scaled this way still perform poorly as a language model, and even underperform similarly-sized HMMs. This work introduces \emph{SimplePCFG}, a simple PCFG formalism with independent left and right productions. Despite imposing a stronger independence assumption than the low-rank approach, we find that this formalism scales more effectively both as a language model and as an unsupervised parser. As an unsupervised parser, our simple PCFG obtains an average F1 of 65.1 on the English PTB, and as a language model, it obtains a perplexity of 119.0, outperforming similarly-sized low-rank PCFGs. We further introduce \emph{FlashInside}, a hardware IO-aware implementation of the inside algorithm for efficiently scaling simple PCFGs.Comment: Accepted to Findings of EMNLP, 202

Joint Entity and Relation Extraction with Span Pruning and Hypergraph Neural Networks

Entity and Relation Extraction (ERE) is an important task in information extraction. Recent marker-based pipeline models achieve state-of-the-art performance, but still suffer from the error propagation issue. Also, most of current ERE models do not take into account higher-order interactions between multiple entities and relations, while higher-order modeling could be beneficial.In this work, we propose HyperGraph neural network for ERE (\hgnn{}), which is built upon the PL-marker (a state-of-the-art marker-based pipleline model). To alleviate error propagation,we use a high-recall pruner mechanism to transfer the burden of entity identification and labeling from the NER module to the joint module of our model. For higher-order modeling, we build a hypergraph, where nodes are entities (provided by the span pruner) and relations thereof, and hyperedges encode interactions between two different relations or between a relation and its associated subject and object entities. We then run a hypergraph neural network for higher-order inference by applying message passing over the built hypergraph. Experiments on three widely used benchmarks (\acef{}, \ace{} and \scierc{}) for ERE task show significant improvements over the previous state-of-the-art PL-marker.Comment: Accepted to Proceedings of EMNLP, 202

A Beam-Steering Reflectarray Antenna with Arbitrary Linear-Polarization Reconfiguration

This work presents a beam-steering reflectarray antenna capable of achieving arbitrary linear polarization (LP) reconfiguration. It utilizes a dual-circular polarization (CP) reconfigurable reflectarray, along with an LP feed horn, to synthesize a LP beam by combining two reflected CP beams in the same direction. The LP states can be dynamically adjusted by tuning the phase constants of the array, which correspondingly modify the wave phases. Experimental validation of the proposed polarization synthesis concept is conducted using a 16$\times$16 dual-CP 1-bit reconfigurable reflectarray operating at 16.8 GHz. This reflectarray generates reconfigurable LP waves with polarization states of LP(0$^\circ$), LP(45$^\circ$), LP(90$^\circ$) and LP(135$^\circ$). Furthermore, it demonstrates the capability to perform beam scanning, allowing for versatile beam manipulation. The application of this polarization-reconfigurable beam-steering reflectarray is pertinent to beam alignment and polarization synchronization in various wireless communication scenarios, including satellite communication and mobile communication

INTERNATIONAL TRADE AND GENDER WAGE GAP IN CHINA

It is a new field to analyze how foreign trade impacts gender wage gap in China. Combining Chinese Household Income Project (CHIP) in 2002 and 2007, the paper aims at researching the impacts of international trade on gender wage discrimination. The paper finds that the development of foreign trade will increase gender wage inequality, which contradicts the neoclassical theory. Specifically, in the aspect of trade dependence, the import dependence and total trade dependence has a statistically significant and positive impact on gender wage gap. From the perspective of mode of trade, compared with processing trade dependency, the import dependency of general trade and foreign trade dependency have more statistically significant impacts on gender wage gap, and the impact of import of general trade on gender wage gap is sizable and statistically significant. From the perspective price, price of trade has a negative impact on gender wage gap, but compared with the price changes of total trade and processing trade, only import price of general trade and total price of import and export have statistically significant impacts on gender wage gap. Finally, changes of terms of trade have a positive impact on gender wage gap, but the impact is not statistically significant

Physical essence of propagable fractional-strength optical vortices in free space

Fractional-order vector vortex beams are recently demonstrated to be new carriers of fractional-strength optical vortices. However, why can those new vortex beams formed by the combination of both unstable states propagate stably in free space? Here, we solve this scientific problem by revealing the physical essence of propagable fractional-strength optical vortices in free space.Three new understandings regarding those peculiar vortex beams are therefore proposed, namely Abbe diffraction limit, phase evolution of vortex beam, and phase binary time vector property.For the first one, owing to Abbe diffraction limit, the inherent polarization modes are intertwined together, thereby maintaining the entire peculiar vortex beams in free space. For the second one, we demonstrate the phase evolution of vortex beam, which is the physical reason of polarization rotation of fractional-order VVBs. For the third one, the phase is not merely a scalar attribute of light beam, but manifests a binary time vector property. This work provides entirely different physical viewpoints on the phase of vortex beam and Abbe diffraction limit, which may deepen our knowledge on the behavior of light beam in classical optics