物理与天体物理最新文献

{"title":"Beta-functions and RG flows for holographic QCD with heavy and light quarks: Isotropic case","authors":"Irina Ya. Aref’eva, Ali Hajilou, Pavel Slepov, Marina Usova","doi":"10.1103/physrevd.111.046013","DOIUrl":"https://doi.org/10.1103/physrevd.111.046013","url":null,"abstract":"In a previous paper [I. Y. Aref’eva , Running coupling for holographic QCD with heavy and light quarks: Isotropic case, ], we investigated the dependence of the running coupling constant on temperature and chemical potential for holographic models of the light and heavy quarks, supported by an Einstein-dilaton-Maxwell action. In this paper, we study the dependence of the corresponding β</a:mi></a:mrow></a:math>-functions on the temperature and the chemical potential. As in the previous paper, we give special attention to the behavior of the <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:mi>β</c:mi></c:mrow></c:math>-functions near the first order phase transitions. We consider different types of boundary conditions for the dilaton. Only one of the possible boundary conditions yields results that agree with lattice calculations at zero chemical potential. The corresponding <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mi>β</e:mi></e:math>-functions are negative and exhibit jumps at the first order phase transitions. We also show that the renormalization group fluxes are invariant with respect to the choice of the boundary conditions and that our exact solutions for the light and heavy quarks are unstable, as expected, given their negative dilaton potentials. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"10 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unitarity bounds with subthreshold and anomalous cuts for b -hadron decays","authors":"Abinand Gopal, Nico Gubernari","doi":"10.1103/physrevd.111.l031501","DOIUrl":"https://doi.org/10.1103/physrevd.111.l031501","url":null,"abstract":"We derive a generalization of the Boyd-Grinstein-Lebed (BGL) parametrization. Most form factors (FFs) in b</a:mi></a:math>-hadron decays exhibit additional branch cuts—namely subthreshold and anomalous branch cuts—beyond the “standard” unitarity cut. These additional cuts cannot be adequately accounted for by the BGL parametrization. For instance, these cuts arise in the FFs for <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mi>B</c:mi><c:mo stretchy=\"false\">→</c:mo><c:msup><c:mi>D</c:mi><c:mrow><c:mo stretchy=\"false\">(</c:mo><c:mo>*</c:mo><c:mo stretchy=\"false\">)</c:mo></c:mrow></c:msup></c:math>, <h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><h:mi>B</h:mi><h:mo stretchy=\"false\">→</h:mo><h:msup><h:mi>K</h:mi><h:mrow><h:mo stretchy=\"false\">(</h:mo><h:mo>*</h:mo><h:mo stretchy=\"false\">)</h:mo></h:mrow></h:msup></h:math>, and <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><m:msub><m:mi mathvariant=\"normal\">Λ</m:mi><m:mi>b</m:mi></m:msub><m:mo stretchy=\"false\">→</m:mo><m:mi mathvariant=\"normal\">Λ</m:mi></m:math> processes, which are particularly relevant from a phenomenological standpoint. We demonstrate how to parametrize such FFs and derive unitarity bounds in the presence of subthreshold and/or anomalous branch cuts. Our work paves the way for a wide range of new FF analyses based solely on first principles, thereby minimizing systematic uncertainties. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"4 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polarization-insensitive microwave power receiving composite array based on reflection phase gradient metasurfaces","authors":"Yi-Zhe Huang, Qiang Yang, Han Xiong, Huai-Qing Zhang","doi":"10.1063/5.0248205","DOIUrl":"https://doi.org/10.1063/5.0248205","url":null,"abstract":"This paper presents a polarization-insensitive microwave power receiving composite metasurface array. The composite array consists of a reflection phase gradient metasurface array and a horizontal omnidirectional antenna, with a central operating frequency of 5.8 GHz. The reflection phase gradient metasurface array elements are insensitive to the polarization of the incident wave and are arranged radially around the array center. This configuration creates a radial reflection phase gradient that efficiently converts incident plane waves of different polarizations into surface waves converging toward the center. The surface wave energy is then extracted by the horizontal omnidirectional antenna and converted into direct current (DC) by a rectifier. Numerical simulations demonstrate that the composite array maintains effective surface wave excitation and propagation toward the center for both circularly polarized and various horizontally polarized plane waves, achieving a plane wave-to-surface wave conversion efficiency of 74.89%. Experimental validation shows that the proposed array achieves a maximum energy collection efficiency of 62.23% and an RF-DC conversion efficiency of 39.96% over a broad frequency range of 5.6–6.0 GHz. This study achieves polarization insensitivity while simultaneously enhancing the operational efficiency of microwave energy receivers. The results offer a valuable design reference for leveraging reflection phase gradient arrays in wireless power transfer applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"10 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced near-infrared photoresponse of SnS2 nanosheets by Er–Yb co-doping","authors":"Lei Wang, Tengfei Huang, Ruipeng Hou, Baocheng Yang","doi":"10.1063/5.0249415","DOIUrl":"https://doi.org/10.1063/5.0249415","url":null,"abstract":"Rare earth (RE) ions are important dopants to modulate semiconductor properties because of their abundant energy levels. Herein, a simple Er–Yb co-doping strategy was developed to enhance the near-infrared optoelectronic properties of SnS2 nanosheets. The constructed device based on Er–Yb co-doping SnS2 has a detectivity of ∼4.97 × 108 Jones at 980 nm. The enhanced photoresponse of the doped system at 980 nm could be attributed to the upconversion behavior of the Er–Yb ion pairs. The Yb3+ ions as sensitizers significantly enhance the upconversion emission and near-infrared photoresponse properties of the material. The energy transfer from Yb3+ to Er3+ ions can occur between different layers of co-doping nanosheets by investigating the properties of the constructed SnS2:Er/SnS2:Yb homojunction nanosheets. Density functional theory calculations reveal that Er or Yb doping introduces slight structural and charge distribution changes owing to the similarity in the metal–atom coordination structure between SnS2 and RE sulfide. Our study demonstrates that RE doping is an effective way to improve the near-infrared photoresponse of 2D materials and clarifies the relationship between luminescence and photoelectric properties.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"52 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced piezoelectricity in TiSXY monolayers based on electronegative polar moments effect","authors":"Dai-Song Tang, Yu-Qing Luo, Dan-Yang Zhu, Jun-Hui Wang, Xian-Tong Shao, Shou-Xin Cui, Xiao-Chun Wang","doi":"10.1063/5.0251468","DOIUrl":"https://doi.org/10.1063/5.0251468","url":null,"abstract":"It is a challenge to find the relationship between the microscopic property of atoms in monolayers and the macroscopic piezoelectricity of monolayer. By first-principles calculation, we find not only the super-dipole moment (SDM) effect but also the electronegative polar moments (EPMs) effect, which can lead to the remarkable piezoelectricity in TiSXY monolayers. The SDM and EPM effects can deepen the understanding of the piezoelectric physical mechanism and provide the design strategy for ultrathin nano-devices.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"52 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using the STIX background detector as a proxy for GOES","authors":"Muriel Zoë Stiefel, Matej Kuhar, Olivier Limousin, Ewan C. M. Dickson, Anna Volpara, Gordon J. Hurford, Säm Krucker","doi":"10.1051/0004-6361/202452574","DOIUrl":"https://doi.org/10.1051/0004-6361/202452574","url":null,"abstract":"<i>Context.<i/> The Spectrometer/Telescope for Imaging X-Rays (STIX) on board Solar Orbiter was designed to observe solar flares in the X-ray range of 4−150 keV, providing spectral, temporal, and spatial information. Besides 30 imaging detectors, STIX has two additional detectors: the coarse flare locator (CFL) and the background (BKG) detector, which are used in the present study. Flares observed from Earth are classified using their peak X-ray flux observed by the Geostationary Operational Environmental Satellite (GOES) instruments. Given to the Solar Orbiter mission design, roughly half of all flares observed by STIX are located on the backside of the Sun. These flares lack a GOES-class classification.<i>Aims.<i/> In this paper, we describe the calibration of the BKG detector aperture sizes. Using the calibrated measurements of the BKG detector, we explore the relationship between the peak flux for flares jointly observed by STIX and GOES. This allows us to estimate the GOES flare classes of backside flares using STIX measurements.<i>Methods.<i/> We looked at the 500 largest flares observed by both STIX and GOES in the time range February 2021 to April 2023. The aperture size calibration was done by comparing 4−10 keV counts of the BKG detector with the CFL measurements. In a second step, we correlated the calibrated STIX BKG peak flux with the GOES peak flux for individual flares.<i>Results.<i/> We calibrated the BKG detector aperture sizes of STIX, which are now ready to be implemented into the ground-software (GSW) of STIX. Furthermore, we showed that for the larger flares (C class and above) a close power law fit exists between the STIX BKG and GOES peak flux, with a Pearson correlation coefficient of 0.97. This correlation provides a GOES proxy with a one sigma uncertainty of ≈11%. We were able to show that the BKG detector can reliably measure a broad range of GOES flare classes from roughly B5 up to at least X85 (assuming a radial distance of 1 AU). This makes it an interesting detector-concept for future space weather missions. Thus far, the largest flare observed by STIX to date is an estimated X16.5 ± 1.8 backside flare of May 20, 2024.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"44 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143375706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The relation between black hole spin, star formation rate, and black hole mass for supermassive black holes","authors":"Yongyun Chen, Qiusheng Gu, Junhui Fan, Xiaotong Guo, Dingrong Xiong, Xiaoling Yu, Xiaogu Zhong, Nan Ding","doi":"10.1051/0004-6361/202452655","DOIUrl":"https://doi.org/10.1051/0004-6361/202452655","url":null,"abstract":"Both theoretical models and observational evidence indicate that jets and/or outflows driven by central active supermassive black holes exert a significant feedback effect on the overall properties of their host galaxies. Theoretical models suggest that the spin of supermassive black holes drives relativistic jets. Therefore, we investigate the relationship between black hole spin, star formation rate, and black hole mass using a sample of 48 low-redshift supermassive black holes. By performing multiband fitting of spectral energy distribution, we derive the star formation rates and stellar masses of the host galaxies harbouring these supermassive black holes. Our main results are as follows: (i) For black holes with masses <i>M<i/><sub>BH<sub/> ≲ 10<sup>6.5<sup/> <i>M<i/><sub>⊙<sub/>, the spin increases with increasing black hole mass, suggesting that black hole growth is primarily driven by gas accretion, particularly in the coherent gas accretion regime. Conversely, for black holes with masses <i>M<i/><sub>BH<sub/> ≳ 10<sup>7.5<sup/> <i>M<i/><sub>⊙<sub/>, the spin decreases with increasing black hole mass, indicating that growth occurs mainly through mergers, inducing chaotic accretion. (ii) At low star formation rates, black hole spin increases with increasing star formation rates, consistent with gas accretion. However, at high star formation rates, black hole spin decreases with increasing star formation rates, suggesting black hole mergers. The value of the black hole spin may be used to diagnose the star formation rate of the host galaxies through active galactic nuclei activities. (iii) Our data and analysis confirm the well-known relation between stellar mass and black hole mass, with the fitting function log <i>M<i/><sub>BH<sub/> = 0.57log <i>M<i/><sub>*<sub/> + 1.94.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"29 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143375748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum complexity phase transitions in monitored random circuits","authors":"Ryotaro Suzuki, Jonas Haferkamp, Jens Eisert, Philippe Faist","doi":"10.22331/q-2025-02-10-1627","DOIUrl":"https://doi.org/10.22331/q-2025-02-10-1627","url":null,"abstract":"Recently, the dynamics of quantum systems that involve both unitary evolution and quantum measurements have attracted attention due to the exotic phenomenon of measurement-induced phase transitions. The latter refers to a sudden change in a property of a state of $n$ qubits, such as its entanglement entropy, depending on the rate at which individual qubits are measured. At the same time, quantum complexity emerged as a key quantity for the identification of complex behaviour in quantum many-body dynamics. In this work, we investigate the dynamics of the quantum state complexity in monitored random circuits, where $n$ qubits evolve according to a random unitary circuit and are individually measured with a fixed probability at each time step. We find that the evolution of the exact quantum state complexity undergoes a phase transition when changing the measurement rate. Below a critical measurement rate, the complexity grows at least linearly in time until saturating to a value $e^{Omega(n)}$. Above, the complexity does not exceed $operatorname{poly}(n)$. In our proof, we make use of percolation theory to find paths along which an exponentially long quantum computation can be run below the critical rate, and to identify events where the state complexity is reset to zero above the critical rate. We lower bound the exact state complexity in the former regime using recently developed techniques from algebraic geometry. Our results combine quantum complexity growth, phase transitions, and computation with measurements to help understand the behavior of monitored random circuits and to make progress towards determining the computational power of measurements in many-body systems.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"23 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143375502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Key reconciliation protocol for quantum key distribution","authors":"Neha Sharma,&nbsp;Vikas Saxena,&nbsp;Vinay Chamola,&nbsp;Vikas Hassija","doi":"10.1140/epjqt/s40507-025-00319-4","DOIUrl":"10.1140/epjqt/s40507-025-00319-4","url":null,"abstract":"<div><p>In quantum cryptography, secret communications are delivered through a quantum channel. One of the most important breakthroughs in quantum cryptography has been the quantum key distribution (QKD). This process enables two distant parties to share secure communications based on physical laws. However, eavesdroppers can still interrupt the communication. To overcome this, we propose a different way to detect the presence of Eve through the polynomial interpolation technique. This technique also allows us for key verification. This approach prevents the receiver as well as the intruder from discovering the sender’s fundamental basis. To fully utilize IBM quantum computers’ quantum computing capabilities, this paper attempts to show % error against alpha (strength of eavesdropping) and the impact of noise on the success probability of the desired key bits. Furthermore, the success probability under depolarizing noise is explained for different qubit counts. In the enhanced QKD protocol, using polynomial interpolation for reconciliation shows a 50% probability of successful key generation. This is even when the noise is increased to the maximum capacity.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00319-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards cosmological inference on unlabeled out-of-distribution HI observational data","authors":"Sambatra Andrianomena,&nbsp;Sultan Hassan","doi":"10.1007/s10509-025-04405-y","DOIUrl":"10.1007/s10509-025-04405-y","url":null,"abstract":"<div><p>We present an approach that can be utilized in order to account for the covariate shift between two datasets of the same observable with different distributions. This helps improve the generalizability of a neural network model trained on in-distribution samples (IDs) when inferring cosmology at the field level on out-of-distribution samples (OODs) of <i>unknown labels</i>. We make use of HI maps from the two simulation suites in CAMELS, IllustrisTNG and SIMBA. We consider two different techniques, namely adversarial approach and optimal transport, to adapt a target network whose initial weights are those of a source network pre-trained on a labeled dataset. Results show that after adaptation, salient features that are extracted by source and target encoders are well aligned in the embedding space. This indicates that the target encoder has learned the representations of the target domain via the adversarial training and optimal transport. Furthermore, in all scenarios considered in our analyses, the target encoder, which does not have access to any labels (<span>(Omega _{mathrm{m}})</span>) during adaptation phase, is able to retrieve the underlying <span>(Omega _{mathrm{m}})</span> from out-of-distribution maps to a great accuracy of <span>(R^{2})</span> score ≥ 0.9, comparable to the performance of the source encoder trained in a supervised learning setup. We further test the viability of the techniques when only a few out-of-distribution instances are available for training and find that the target encoder still reasonably recovers the matter density. Our approach is critical in extracting information from upcoming large scale surveys.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"370 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143373255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}