Communications in Theoretical Physics最新文献

{"title":"Quantum algorithms for matrix operations and linear systems of equations","authors":"Wentao Qi, Alexandr I Zenchuk, Asutosh Kumar, Junde Wu","doi":"10.1088/1572-9494/ad2366","DOIUrl":"https://doi.org/10.1088/1572-9494/ad2366","url":null,"abstract":"Fundamental matrix operations and solving linear systems of equations are ubiquitous in scientific investigations. Using the ‘sender-receiver’ model, we propose quantum algorithms for matrix operations such as matrix-vector product, matrix-matrix product, the sum of two matrices, and the calculation of determinant and inverse matrix. We encode the matrix entries into the probability amplitudes of the pure initial states of senders. After applying proper unitary transformation to the complete quantum system, the desired result can be found in certain blocks of the receiver’s density matrix. These quantum protocols can be used as subroutines in other quantum schemes. Furthermore, we present an alternative quantum algorithm for solving linear systems of equations.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Cold plasma-induced effects on electromagnetic wave scattering in waveguides: a mode-matching analysis","authors":"Shahana Rizvi, Muhammad Afzal","doi":"10.1088/1572-9494/ad23db","DOIUrl":"https://doi.org/10.1088/1572-9494/ad23db","url":null,"abstract":"This article presents advancements in an analytical mode-matching technique for studying electromagnetic wave propagation in a parallel-plate metallic rectangular waveguide. This technique involves projecting the solution onto basis functions and solving linear algebraic systems to determine scattering amplitudes. The accuracy of this method is validated via numerical assessments, which involve the reconstruction of matching conditions and conservation laws. The study highlights the impact of geometric and material variations on reflection and transmission phenomena in the waveguide.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Q-homotopy analysis method for time-fractional Newell–Whitehead equation and time-fractional generalized Hirota–Satsuma coupled KdV system","authors":"Di Liu, Qiongya Gu, Lizhen Wang","doi":"10.1088/1572-9494/ad2364","DOIUrl":"https://doi.org/10.1088/1572-9494/ad2364","url":null,"abstract":"In this paper, two types of fractional nonlinear equations in Caputo sense, time-fractional Newell–Whitehead equation (FNWE) and time-fractional generalized Hirota–Satsuma coupled KdV system (HS-cKdVS), are investigated by means of the q-homotopy analysis method (q-HAM). The approximate solutions of the proposed equations are constructed in the form of a convergent series and are compared with the corresponding exact solutions. Due to the presence of the auxiliary parameter <italic toggle=\"yes\">h</italic> in this method, just a few terms of the series solution are required in order to obtain better approximation. For the sake of visualization, the numerical results obtained in this paper are graphically displayed with the help of Maple.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Tighter sum uncertainty relations via (α, β, γ) weighted Wigner–Yanase–Dyson skew information","authors":"Cong Xu, Zhaoqi Wu, Shao-Ming Fei","doi":"10.1088/1572-9494/ad216b","DOIUrl":"https://doi.org/10.1088/1572-9494/ad216b","url":null,"abstract":"We establish tighter uncertainty relations for arbitrary finite observables via (<italic toggle=\"yes\">α</italic>, <italic toggle=\"yes\">β</italic>, <italic toggle=\"yes\">γ</italic>) weighted Wigner–Yanase–Dyson ((<italic toggle=\"yes\">α</italic>, <italic toggle=\"yes\">β</italic>, <italic toggle=\"yes\">γ</italic>) WWYD) skew information. The results are also applicable to the (<italic toggle=\"yes\">α</italic>, <italic toggle=\"yes\">γ</italic>) weighted Wigner–Yanase–Dyson ((<italic toggle=\"yes\">α</italic>, <italic toggle=\"yes\">γ</italic>) WWYD) skew information and the weighted Wigner–Yanase–Dyson (WWYD) skew information. We also present tighter lower bounds for quantum channels and unitary channels via (<italic toggle=\"yes\">α</italic>, <italic toggle=\"yes\">β</italic>, <italic toggle=\"yes\">γ</italic>) modified weighted Wigner–Yanase–Dyson ((<italic toggle=\"yes\">α</italic>, <italic toggle=\"yes\">β</italic>, <italic toggle=\"yes\">γ</italic>) MWWYD) skew information. Detailed examples are provided to illustrate the tightness of our uncertainty relations.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 quasi-Gramian solution of a non-commutative extension of the higher-order nonlinear Schrödinger equation","authors":"H W A Riaz, J Lin","doi":"10.1088/1572-9494/ad244f","DOIUrl":"https://doi.org/10.1088/1572-9494/ad244f","url":null,"abstract":"The nonlinear Schrödinger (NLS) equation, which incorporates higher-order dispersive terms, is widely employed in the theoretical analysis of various physical phenomena. In this study, we explore the non-commutative extension of the higher-order NLS equation. We treat real or complex-valued functions, such as <italic toggle=\"yes\">g</italic>\u0000₁ = <italic toggle=\"yes\">g</italic>\u0000₁(<italic toggle=\"yes\">x</italic>, <italic toggle=\"yes\">t</italic>) and <italic toggle=\"yes\">g</italic>\u0000₂ = <italic toggle=\"yes\">g</italic>\u0000₂(<italic toggle=\"yes\">x</italic>, <italic toggle=\"yes\">t</italic>) as non-commutative, and employ the Lax pair associated with the evolution equation, as in the commutation case. We derive the quasi-Gramian solution of the system by employing a binary Darboux transformation. The soliton solutions are presented explicitly within the framework of quasideterminants. To visually understand the dynamics and solutions in the given example, we also provide simulations illustrating the associated profiles. Moreover, the solution can be used to study the stability of plane waves and to understand the generation of periodic patterns within the context of modulational instability.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"On the improved dynamics approach in loop quantum black holes","authors":"Hongchao Zhang, Wen-Cong Gan, Yungui Gong, Anzhong Wang","doi":"10.1088/1572-9494/ad23dc","DOIUrl":"https://doi.org/10.1088/1572-9494/ad23dc","url":null,"abstract":"In this paper, we consider the Böhmer–Vandersloot (BV) model of loop quantum black holes obtained from the improved dynamics approach. We adopt the Saini–Singh gauge, in which it was found analytically that the BV spacetime is geodesically complete. We show that black/white hole horizons do not exist in this geodesically complete spacetime. Instead, there exists only an infinite number of transition surfaces, which always separate trapped regions from anti-trapped ones. Comments on the improved dynamics approach adopted in other models of loop quantum black holes are also given.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"An improved effective liquid drop model for cluster radioactivity","authors":"JianPo Cui, FengZhu Xing, YongHao Gao, LiQian Qi, YanZhao Wang, JianZhong Gu","doi":"10.1088/1572-9494/ad2367","DOIUrl":"https://doi.org/10.1088/1572-9494/ad2367","url":null,"abstract":"The effective liquid drop model (ELDM) is improved by introducing an accurate nuclear charge radius formula and an analytic expression for assaulting frequency. Within the improved effective liquid drop model (IMELDM), the experimental cluster radioactivity half-lives of the trans-lead region are calculated. It is shown that the accuracy of the IMELDM is improved compared with that of the ELDM. At last, the cluster radioactivity half-lives that are experimentally unavailable for the trans-lead nuclei are predicted by the IMELDM. These predictions may be useful for searching for new candidates for cluster radioactivity in future experiments.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Investigation of proton structure function F2p at HERA in light of an analytical solution to the Balitsky–Kovchegov equation","authors":"Ranjan Saikia, Pragyan Phukan, Jayanta Kumar Sarma","doi":"10.1088/1572-9494/ad260d","DOIUrl":"https://doi.org/10.1088/1572-9494/ad260d","url":null,"abstract":"In this paper, the proton structure function <inline-formula>\u0000<tex-math>\u0000<?CDATA ${F}_{2}^{p}(x,{Q}^{2})$?>\u0000</tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msubsup><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:msubsup><mml:mo stretchy=\"false\">(</mml:mo><mml:mi>x</mml:mi><mml:mo>,</mml:mo><mml:msup><mml:mrow><mml:mi>Q</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo stretchy=\"false\">)</mml:mo></mml:math>\u0000<inline-graphic xlink:href=\"ctpad260dieqn3.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> at small-<italic toggle=\"yes\">x</italic> is investigated using an analytical solution to the Balitsky–Kovchegov (BK) equation. In the context of the color dipole description of deep inelastic scattering (DIS), the structure function <inline-formula>\u0000<tex-math>\u0000<?CDATA ${F}_{2}^{p}(x,{Q}^{2})$?>\u0000</tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msubsup><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:msubsup><mml:mo stretchy=\"false\">(</mml:mo><mml:mi>x</mml:mi><mml:mo>,</mml:mo><mml:msup><mml:mrow><mml:mi>Q</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo stretchy=\"false\">)</mml:mo></mml:math>\u0000<inline-graphic xlink:href=\"ctpad260dieqn4.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> is computed by applying the analytical expression for the scattering amplitude <italic toggle=\"yes\">N</italic>(<italic toggle=\"yes\">k</italic>, <italic toggle=\"yes\">Y</italic>) derived from the BK solution. At transverse momentum <italic toggle=\"yes\">k</italic> and total rapidity <italic toggle=\"yes\">Y</italic>, the scattering amplitude <italic toggle=\"yes\">N</italic>(<italic toggle=\"yes\">k</italic>, <italic toggle=\"yes\">Y</italic>) represents the propagation of the quark-antiquark dipole in the color dipole description of DIS. Using the BK solution we extracted the integrated gluon density <italic toggle=\"yes\">xg</italic>(<italic toggle=\"yes\">x</italic>, <italic toggle=\"yes\">Q</italic>\u0000²) and then compared our theoretical estimation with the LHAPDF global data fits, NNPDF3.1sx and CT18. Finally, we have investigated the behavior of <inline-formula>\u0000<tex-math>\u0000<?CDATA ${F}_{2}^{p}(x,{Q}^{2})$?>\u0000</tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msubsup><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:msubsup><mml:mo stretchy=\"false\">(</mml:mo><mml:mi>x</mml:mi><mml:mo>,</mml:mo><mml:msup><mml:mrow><mml:mi>Q</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo stretchy=\"false\">)</mml:mo></mml:math>\u0000<inline-graphic xlink:href=\"ctpad260dieqn5.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula> in the kinematic region of 10⁻⁵ ≤ <italic toggle=\"yes\">x</italic> ≤ 10⁻² and 2.5 GeV² ≤ <italic toggle=\"yes\">Q</italic>\u0000<sup>2</s","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 dense coding with gravitational cat states","authors":"Saeed Haddadi, Mehrdad Ghominejad, Artur Czerwinski","doi":"10.1088/1572-9494/ad23da","DOIUrl":"https://doi.org/10.1088/1572-9494/ad23da","url":null,"abstract":"A protocol of quantum dense coding with gravitational cat states is proposed. We explore the effects of temperature and system parameters on dense coding capacity and provide an efficient strategy to preserve the quantum advantage of dense coding for these states. Our results may open new opportunities for secure communication and insights into the fundamental nature of gravity in the context of quantum information processing.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Ren-integrable and ren-symmetric integrable systems","authors":"S Y Lou","doi":"10.1088/1572-9494/ad23de","DOIUrl":"https://doi.org/10.1088/1572-9494/ad23de","url":null,"abstract":"A new type of symmetry, ren-symmetry, describing anyon physics and corresponding topological physics, is proposed. Ren-symmetry is a generalization of super-symmetry which is widely applied in super-symmetric physics such as super-symmetric quantum mechanics, super-symmetric gravity, super-symmetric string theory, super-symmetric integrable systems and so on. Super-symmetry and Grassmann numbers are, in some sense, dual conceptions, and it turns out that these conceptions coincide for the ren situation, that is, a similar conception of ren-number (R-number) is devised for ren-symmetry. In particular, some basic results of the R-number and ren-symmetry are exposed which allow one to derive, in principle, some new types of integrable systems including ren-integrable models and ren-symmetric integrable systems. Training examples of ren-integrable KdV-type systems and ren-symmetric KdV equations are explicitly given.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}