Holographic torus correlators of stress tensor in AdS3 /CFT2

Abstract In this work, we investigate holographic correlators of the stress tensor of a conformal field theory (CFT) on a torus within the context of AdS3 /CFT2. To compute the correlators of the stress tensor, we employ the Einstein-Hilbert theory of gravity and perturbatively solve Einstein’s equation in the bulk. In addition, we present an explicit prescription for developing a recurrence relation that simplifies the computation of higher point correlators. Our results show that the correlators and recurrence relation are consistent with known results in CFTs. Additionally, in line with the proposed cutoff-AdS/ T T ¯ $$T\overline{T}$$ -CFT holography, we extend our computation program to investigate holographic torus correlators at a finite cutoff in the AdS3 and derive a parallel recurrence relation associated with higher point correlators

Sex differences in solid pseudopapillary neoplasm of the pancreas: A population‐based study

Abstract Objective Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare tumor. This study aims to examine the clinicopathological features and surgical treatments of SPN and compare the clinical behavior and prognosis between men and women with SPN. Methods We collected the population data of patients with SPN diagnosed between 2004 and 2017 from the SEER database. The Kaplan‐Meier method was used to analyze overall survival (OS) and disease‐specific survival (DSS), and log‐rank tests were used to evaluate the differences between subgroups. Univariate and multivariate Cox regression analyses were performed to screen out prognostic risk factors of SPN. Results A total of 378 patients with SPN were included, with 246 (65.1%) female patients. 1‐, 3‐, and 5‐year overall survival rates were 98.9%, 95.7%, and 93.7%, respectively. Survival analysis revealed that regardless of stage, patients with SPN who underwent surgical interventions still had a significantly better prognosis than those without surgical interventions (P < .001). The patients with lymphatic dissection had a significantly better prognosis than those without lymphatic dissection (P < .001). Moreover, compared with female patients, male patients had significantly poorer OS and DSS (P < .001). Female SPN showed a bimodal age‐frequency distribution with early‐onset incidence at 28 years and late‐onset peak incidence at 62 years, while male SPN presented a unimodal distribution with peak incidence at approximately age 64 years. In female patients, the tumor size in premenopausal females (<65 years old) was significantly larger than that in postmenopausal females (≥65 years old) (P < .001). Clinicopathological characteristic profiles were different not only between male SPN and premenopausal female SPN but also between premenopausal and postmenopausal female SPN. Conclusion SPN presents indolent behavior and predominantly occurs in young women. Regardless of stage, surgical intervention is recommended. Moreover, our study is the first large enough study to demonstrate sex‐related discrepancies in SPN. Thus, different treatment strategies should be designed for patients of different sexes at different ages and hormone therapy is a promising approach for SPN

High-performance, polarization-sensitive, long-wave infrared photodetection via photothermoelectric effect with asymmetric van der Waals contacts

Long-wavelength infrared (LWIR) photodetection is important for heat-seeking technologies, such as thermal imaging, all-weather surveillance, and missile guidance. Among various detection techniques, photothermoelectric (PTE) detectors are promising in that they can realize ultra-broadband photodetection at room temperature without an external power supply. However, their performance in terms of speed, responsivity, and noise level in the LWIR regime still needs further improvement. Here, we demonstrated a high-performance PTE photodetector based on low-symmetry palladium selenide (PdSe2) with asymmetric van der Waals contacts. The temperature gradient induced by asymmetric van der Waals contacts even under global illumination drives carrier diffusion to produce a photovoltage via the PTE effect. A responsivity of over 13 V/W, a response time of ∼50 μs, and a noise equivalent power of less than 7 nW/Hz1/2 are obtained in the 4.6-10.5 μm regime at room temperature. Furthermore, due to the anisotropic absorption of PdSe2, the detector exhibits a linear polarization angle sensitive response with an anisotropy ratio of 2.06 at 4.6 μm and 1.21 at 10.5 μm, respectively. Our proposed device architecture provides an alternative strategy to design high-performance photodetectors in the LWIR regime by utilizing van der Waals layered materials.Ministry of Education (MOE)National Research Foundation (NRF)Accepted versionThis research was also supported partially by National Research Foundation Singapore program (NRF-CRP18- 2017-02 and NRF-CRP22-2019-0007) and Ministry of Education Tier 2 program (MOE2018-T2-1-176)

A two-dimensional mid-infrared optoelectronic retina enabling simultaneous perception and encoding

Infrared machine vision system for object perception and recognition is becoming increasingly important in the Internet of Things era. However, the current system suffers from bulkiness and inefficiency as compared to the human retina with the intelligent and compact neural architecture. Here, we present a retina-inspired mid-infrared (MIR) optoelectronic device based on a two-dimensional (2D) heterostructure for simultaneous data perception and encoding. A single device can perceive the illumination intensity of a MIR stimulus signal, while encoding the intensity into a spike train based on a rate encoding algorithm for subsequent neuromorphic computing with the assistanceofanall-opticalexcitationmechanism, a stochastic near-infrared (NIR) sampling terminal. The device features wide dynamic working range, high encoding precision, and flexible adaption ability to the MIR intensity. Moreover, an inference accuracy more than 96% toMIR MNIST data set encoded by the device is achieved using a trained spiking neural network (SNN).Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)National Medical Research Council (NMRC)National Research Foundation (NRF)Published versionThis work was supported by the Singapore Ministry of Education (MOE-T2EP50120-0009 (Q.J.W.)), Agency for Science, Technology and Research (A*STAR) (A18A7b0058 (Q.J.W.) and A2090b0144 (Q.J.W.)), National Medical Research Council (NMRC) (021528- 00001 (Q.J.W.)), and National Research Foundation Singapore (NRF-CRP22-2019-0007 (Q.J.W.)), National Key Research and Development Program of China (2022YFB2802803 (N.C.)), the Natural Science Foundation of China Project (61925104 (N.C.), 62031011 (N.C.)) and Major Key Project of PCL (N.C.), and F.H. acknowledges the support from the China Scholarship Council

A two-dimensional mid-infrared optoelectronic retina enabling simultaneous perception and encoding

Designing an infrared machine vision system that can efficiently perceive, convert, and process a massive amount of data remains a challenge. Here, the authors present a retina-inspired 2D optoelectronic device based on van der Waals heterostructure that can perform the data perception and spike-encoding simultaneously for night vision, sensing, spectroscopy, and free-space communications