A
bstract
Conformal defects describe the universal behaviors of a conformal field theory (CFT) in the presence of a boundary or more general impurities. The coupled critical system is characterized ...by new conformal anomalies which are analogous to, and generalize those of standalone CFTs. Here we study the conformal
a
- and
c
-anomalies of four dimensional defects in CFTs of general spacetime dimensions greater than four. We prove that under unitary defect renormalization group (RG) flows, the defect
a
-anomaly must decrease, thus establishing the defect
a
-theorem. For conformal defects preserving minimal supersymmetry, the full defect symmetry contains a distinguished U(1)
R
subgroup. We derive the anomaly multiplet relations that express the defect
a
- and
c
-anomalies in terms of the defect (mixed) ’t Hooft anomalies for this U(1)
R
symmetry. Once the U(1)
R
symmetry is identified using the defect
a
-maximization principle which we prove, this enables a non-perturbative pathway to the conformal anomalies of strongly coupled defects. We illustrate our methods by discussing a number of examples including boundaries in five dimensions and codimension-two defects in six dimensions. We also comment on chiral algebra sectors of defect operator algebras and potential conformal collider bounds on defect anomalies.
A
bstract
Quantum field theories (QFT) in the presence of defects exhibit new types of anomalies which play an important role in constraining the defect dynamics and defect renormalization group (RG) ...flows. Here we study surface defects and their anomalies in conformal field theories (CFT) of general spacetime dimensions. When the defect is conformal, it is characterized by a conformal
b
-anomaly analogous to the
c
-anomaly of 2d CFTs. The
b
-theorem states that
b
must monotonically decrease under defect RG flows and was proven by coupling to a spurious defect dilaton. We revisit the proof by deriving explicitly the dilaton effective action for defect RG flow in the free scalar theory. For conformal surface defects preserving
N
= (0
,
2) supersymmetry, we prove a universal relation between the
b
-anomaly and the ’t Hooft anomaly for the U(1)
r
symmetry. We also establish the
b
-extremization principle that identifies the superconformal U(1)
r
symmetry from
N
= (0
,
2) preserving RG flows. Together they provide a powerful tool to extract the
b
-anomaly of strongly coupled surface defects. To illustrate our method, we determine the
b
-anomalies for a number of surface defects in 3d, 4d and 6d SCFTs. We also comment on manifestations of these defect conformal and ’t Hooft anomalies in defect correlation functions.
The four dimensional N=4 super-Yang-Mills (SYM) theory exhibits rich dynamics in the presence of codimension-one conformal defects. The new structure constants of the extended operator algebra ...consist of one-point functions of local operators which are nonvanishing due to the defect insertion and carry nontrivial coupling dependence. We study an important class of half-BPS superconformal defects engineered by D5 branes that share three common directions with the D3 branes and involve Nahm pole configurations for the SYM fields on the D3 brane worldvolume. In the planar large N limit, we obtain non-perturbative results in the 't Hooft coupling λ for the defect one-point functions of both BPS and non-BPS operators, building upon recent progress in localization 1 and integrability methods 2,3.
For BPS operator insertions in the SYM with D5-brane type boundary or interface, we derive an effective two dimensional defect-Yang-Mills (dYM) theory from supersymmetric localization, which gives an efficient way to extract defect observables and generates a novel matrix model for the defect one-point function. By solving the matrix model in the large N limit, we obtain exact results in λ which interpolate between perturbative Feynman diagram contributions in the weak coupling limit and IIB string theory predictions on AdS5×S5 in the strong coupling regime, providing a precision test of AdS/CFT with interface defects. For general non-BPS operators, we develop a non-perturbative bootstrap-type program for integrable boundary states on the worldsheet of the IIB string theory, corresponding to the interface defects in the planar SYM. Such integrable boundary states are constrained by a set of general consistency conditions for which we present explicit solutions that reproduce and extend the known results at weak coupling from integrable spin-chain methods.
The knowledge hiding behavior (KHB) can obstruct the stream of information to decrease the creativity in the organization. This study examines the effect of interpersonal competition on KHB, moral ...disengagement (MD), and work overload (WO). Moreover, this study also examines the impact of MD and WO on KHB. Also, the study examines the mediating role of MD and WO between interpersonal competition and KHB. The study was carried out by quantitative methodology, and 361 employees were engaged to fill the questionnaires employed in manufacturing companies from China. A convenient sampling technique had used for data collection. The findings of this study indicate that interpersonal competition positively and significantly affects KHB, MD, and WO. Moreover, this study established that MD and WO positively and significantly impact KHB. According to the results, MD WO significantly mediates interpersonal competition and KHB. This research is valuable for government, policymakers, and executives of manufacturing companies to establish the appropriate strategies for employees and provide a sustainable environment. This research also offers new visions to managers to know the current events and predict the possible causes that lead to the KHB and what is the possible strategies to eliminate this kind of behavior.
We obtain a large class of new four-dimensional Argyres-Douglas theories by classifying irregular punctures for the six-dimensional (2, 0) superconformal theory of ADE type on a sphere. Along the ...way, we identify the connection between the Hitchin system and threefold singularity descriptions of the same Argyres-Douglas theory. Other constructions such as taking degeneration limits of the irregular puncture, adding an extra regular puncture, and introducing outer-automorphism twists are also discussed. Later we investigate various features of these theories including their Coulomb branch spectrum and central charges.
A
bstract
A global symmetry of a quantum field theory is said to have an ’t Hooft anomaly if it cannot be promoted to a local symmetry of a gauged theory. In this paper, we show that the anomaly is ...also an obstruction to defining symmetric boundary conditions. This applies to Lorentz symmetries with gravitational anomalies as well. For theories with perturbative anomalies, we demonstrate the obstruction by analyzing the Wess-Zumino consistency conditions and current Ward identities in the presence of a boundary. We then recast the problem in terms of symmetry defects and find the same conclusions for anomalies of discrete and orientation-reversing global symmetries, up to the conjecture that global gravitational anomalies, which may not be associated with any diffeomorphism symmetry, also forbid the existence of boundary conditions. This conjecture holds for known gravitational anomalies in
D ≤
3 which allows us to conclude the obstruction result for
D ≤
4.
A
bstract
We study generalized discrete symmetries of quantum field theories in 1+1D generated by topological defect lines with no inverse. In particular, we describe ’t Hooft anomalies and classify ...gapped phases stabilized by these symmetries, including new 1+1D topological phases. The algebra of these operators is not a group but rather is described by their fusion ring and crossing relations, captured algebraically as a fusion category. Such data defines a Turaev-Viro/Levin-Wen model in 2+1D, while a 1+1D system with this fusion category acting as a global symmetry defines a boundary condition. This is akin to gauging a discrete global symmetry at the boundary of Dijkgraaf-Witten theory. We describe how to “ungauge” the fusion category symmetry in these boundary conditions and separate the symmetry-preserving phases from the symmetry-breaking ones. For Tambara-Yamagami categories and their generalizations, which are associated with Kramers-Wannier-like self-dualities under orbifolding, we develop gauge theoretic techniques which simplify the analysis. We include some examples of CFTs with fusion category symmetry derived from Kramers-Wannier-like dualities as an appetizer for the Part II companion paper.
Layer‐by‐layer (LL) processes, i.e., sequential deposition of different active layers, are widely used in the fabrication of organic solar cells (OSCs). Recently, LL vacuum deposition and LL solution ...processes have attracted considerable attention. LL processing presents some advantages over the blend method: a) donor and acceptor layers can be easily and independently controlled and optimized; b) the charge carriers dissociated from excitons at the donor–acceptor interface are confined to each phase, so bimolecular recombination losses can be reduced; c) bilayer geometries enable an easier way for understanding the physical processes taking place at the donor–acceptor interface; d) desired vertical phase separation for charge extraction can be obtained through changing the sequence of donor and acceptor deposition. This report summarizes the recent developments of LL processed OSCs. The remaining problems and challenges, and the key research direction in near future are discussed.
Layer‐by‐layer (LL) processing techniques exhibit some advantages over the traditional blend‐casting technique in organic solar cells. The recent developments of LL vacuum‐deposited and solution‐processed solar cells are summarized.
Yifan Wang works in the field of molecular parasitology with a focus on host-pathogen interactions. In this mSphere of Influence article, he reflects on how papers entitled "A genome-wide CRISPR ...screen in
identifies essential apicomplexan genes" by S. M. Sidik, D. Huet, S. M. Ganesan, M.-H. Huynh, et al. (Cell 166:1423.e12-1435.e12, 2016, https://doi.org/10.1016/j.cell.2016.08.019) and "Mapping host-microbe transcriptional interactions by dual Perturb-seq" by S. Butterworth, K. Kordova, S. Chandrasekaran, K. K. Thomas, et al. (bioRxiv, https://doi.org/10.1101/2023.04.21.537779) made an impact on his research and changed the way he thinks how functional genomics and high-throughput screens provide novel insights into pathogen pathogenesis.
Increasing human activities have caused significant global ecosystem disturbances at various scales. There is an increasing need for effective techniques to quantify and detect ecological changes. ...Remote sensing can serve as a measurement surrogate of spatial changes in ecological conditions. This study has improved a newly-proposed remote sensing based ecological index (RSEI) with a sharpened land surface temperature image and then used the improved index to produce the time series of ecological-status images. The Mann–Kendall test and Theil–Sen estimator were employed to evaluate the significance of the trend of the RSEI time series and the direction of change. The change vector analysis (CVA) was employed to detect ecological changes based on the image series. This RSEI-CVA approach was applied to Fujian province, China to quantify and detect the ecological changes of the province in a period from 2002 to 2017 using Moderate Resolution Imaging Spectroradiometer (MODIS) data. The result shows that the RSEI-CVA method can effectively quantify and detect spatiotemporal changes in ecological conditions of the province, which reveals an ecological improvement in the province during the study period. This is indicated by the rise of mean RSEI scores from 0.794 to 0.852 due to an increase in forest area by 7078 km2. Nevertheless, CVA-based change detection has detected ecological declines in the eastern coastal areas of the province. This study shows that the RSEI-CVA approach would serve as a prototype method to quantify and detect ecological changes and hence promote ecological change detection at various scales.
PDF
