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1تقرير
المؤلفون: Benincasa, Paolo, Dian, Gabriele
المصدر: doi:10.3204/PUBDB-2024-00063
مصطلحات موضوعية: correlation function, geometry, wave function, buildings, Robertson-Walker, factorization, triangulation, surface, toy model, Feynman graph, structure, cosmological model
جغرافية الموضوع: DE
الوصف: We provide a first principle definition of cosmological correlation functions for a large class of scalar toy models in arbitrary FRW cosmologies, in terms of novel geometries we name {\it weighted cosmological polytopes}. Each of these geometries encodes a universal rational integrand associated to a given Feynman graph. In this picture, all the possible ways of organising, and computing, cosmological correlators correspond to triangulations and subdivisions of the geometry, containing the in-in representation, the one in terms of wavefunction coefficients and many others. We also provide two novel contour integral representations, one connecting higher and lower loop correlators and the other one expressing any of them in terms of a building block. We study the boundary structure of these geometries allowing us to prove factorisation properties and Steinmann-like relations when single and sequential discontinuities are approached. We also show that correlators must satisfy novel vanishing conditions. As the weighted cosmological polytopes can be obtained as an orientation-changing operation onto a certain subdivision of the cosmological polytopes encoding the wavefunction of the universe, this picture allows us to sharpen how the properties of cosmological correlators are inherited from the ones of the wavefunction. From a mathematical perspective, we also provide an in-depth characterisation of their adjoint surface.
العلاقة: info:eu-repo/semantics/altIdentifier/arxiv/arXiv:2401.05207; https://bib-pubdb1.desy.de/record/601026Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2024-00063%22Test
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2مؤتمر
المؤلفون: Borinsky, Michael, Munch, Henrik, Tellander, Felix
المصدر: Proceedings of Science / International School for Advanced Studies (EPS-HEP2023), 499 (2023). doi:10.22323/1.449.0499 ; The European Physical Society Conference on High Energy Physics, EPS-HEP2023, Hamburg, Germany, 2023-08-21 - 2023-08-26
مصطلحات موضوعية: info:eu-repo/classification/ddc/530, geometry, deformation, graph theory, programming, Feynman graph, numerical calculations, mathematical methods
جغرافية الموضوع: DE
الوصف: The software feyntrop for direct numerical evaluation of Feynman integrals is presented. We focus on the underlying combinatorics and polytopal geometries facilitating these methods. Especially matroids, generalized permutohedra and normality are discussed in detail.
العلاقة: info:eu-repo/semantics/altIdentifier/issn/1824-8039; info:eu-repo/semantics/altIdentifier/arxiv/arXiv:2310.19890; https://bib-pubdb1.desy.de/record/597170Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2023-06460%22Test
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3دورية أكاديمية
المصدر: Journal of high energy physics 10(10), 161 (2023). doi:10.1007/JHEP10(2023)161
مصطلحات موضوعية: info:eu-repo/classification/ddc/530, Feynman graph, loop integral: 1, differential equations, Jacobi identity, Landau-Lifshitz model, singularity, kinematics, Differential and Algebraic Geometry, Higher-Order Perturbative Calculations, Scattering Amplitudes
جغرافية الموضوع: DE
الوصف: We provide evidence through two loops, that rational letters of polylogarithmic Feynman integrals are captured by the Landau equations, when the latter are recast as a polynomial of the kinematic variables of the integral, known as the principal $A$-determinant. Focusing on one loop, we further show that all square-root letters may also be obtained, by re-factorizing the principal $A$-determinant with the help of Jacobi identities. We verify our findings by explicitly constructing canonical differential equations for the one-loop integrals in both odd and even dimensions of loop momenta, also finding agreement with earlier results in the literature for the latter case. We provide a computer implementation of our results for the principal $A$-determinant, symbol alphabets and canonical differential equations in an accompanying Mathematica file. Finally, we study the question of when a one-loop integral satisfies the Cohen-Macaulay property and show that for almost all choices of kinematics the Cohen-Macaulay property holds. Throughout, in our approach to Feynman integrals, we make extensive use of the Gel'fand, Graev, Kapranov and Zelevinskiĭ on what are now commonly called GKZ-hypergeometric systems whose singularities are described by the principal $A$-determinant.
العلاقة: info:eu-repo/semantics/altIdentifier/issn/1029-8479; info:eu-repo/semantics/altIdentifier/arxiv/arXiv:2304.02629; info:eu-repo/semantics/altIdentifier/issn/1126-6708; info:eu-repo/semantics/altIdentifier/issn/1127-2236; https://bib-pubdb1.desy.de/record/597357Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2023-06571%22Test
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4دورية أكاديمية
المؤلفون: Dlapa, Christoph, Henn, Johannes M., Wagner, Fabian J.
المصدر: Journal of high energy physics 08(8), 120 (2023). doi:10.1007/JHEP08(2023)120
مصطلحات موضوعية: info:eu-repo/classification/ddc/530, mathematical methods, perturbation theory: higher-order, Feynman graph: higher-order, loop integral, differential equations
جغرافية الموضوع: DE
الوصف: In recent years, differential equations have become the method of choice to compute multi-loop Feynman integrals. Whenever they can be cast into canonical form, their solution in terms of special functions is straightforward. Recently, progress has been made in understanding the precise canonical form for Feynman integrals involving elliptic polylogarithms. In this article, we make use of an algorithmic approach that proves powerful to find canonical forms for these cases. To illustrate the method, we reproduce several known canonical forms from the literature and present examples where a canonical form is deduced for the first time. Together with this article, we also release an update for INITIAL, a publicly available Mathematica implementation of the algorithm.
العلاقة: info:eu-repo/semantics/altIdentifier/arxiv/arXiv:2211.16357; info:eu-repo/semantics/altIdentifier/issn/1029-8479; info:eu-repo/semantics/altIdentifier/wos/WOS:001052857600005; info:eu-repo/semantics/altIdentifier/issn/1126-6708; info:eu-repo/semantics/altIdentifier/issn/1127-2236; https://bib-pubdb1.desy.de/record/589375Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2023-05155%22Test
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5دورية أكاديمية
المؤلفون: Ciuchini, Marco, Fedele, Marco, Franco, Enrico, Paul, Ayan, Silvestrini, Luca, Valli, Mauro
المصدر: The European physical journal / C 83(1), 64 (2023). doi:10.1140/epjc/s10052-023-11191-w
مصطلحات موضوعية: info:eu-repo/classification/ddc/530, new physics, lepton: flavor: universality, lepton: universality: violation, B: semileptonic decay, B: branching ratio: ratio, decay: flavor changing, Feynman graph: penguin, helicity: dependence, helicity: amplitude analysis, amplitude analysis: penguin, B+ --> K+ lepton antilepton, B0 --> K0(S) lepton antilepton, B0 --> K*(892)0 lepton antilepton
جغرافية الموضوع: DE
الوصف: The LHCb experiment has recently presented new results on Lepton Universality Violation (LUV) in $B \rightarrow K^{(*)} \ell ^+ \ell ^-$ decays involving $K_S$ in the final state, which strengthen the recent evidence of LUV obtained in $B^+ \rightarrow K^{+} \ell ^+ \ell ^-$ decays and the previous measurements of $B \rightarrow K^{*0} \ell ^+ \ell ^-$. While LUV observables in the Standard Model are theoretically clean, their predictions in New Physics scenarios are sensitive to the details of the hadronic dynamics, and in particular of the charming penguin contribution. In this work, we show how a conservative treatment of hadronic uncertainties is crucial not only to assess the significance of deviations from the Standard Model but also to obtain a conservative picture of the New Physics responsible for LUV. Adopting a very general parameterization of charming penguins, we find that: (i) current data hint at a sizable $q^2$ and helicity dependence of charm loop amplitudes; (ii) conservative NP solutions to B anomalies favour a left-handed or an axial lepton coupling rather than a vector one.
العلاقة: info:eu-repo/semantics/altIdentifier/arxiv/arXiv:2110.10126; info:eu-repo/semantics/altIdentifier/wos/WOS:000922349700006; info:eu-repo/semantics/altIdentifier/issn/1434-6052; info:eu-repo/semantics/altIdentifier/issn/1434-6044; https://bib-pubdb1.desy.de/record/600288Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2023-07856%22Test
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6دورية أكاديمية
المؤلفون: Blümlein, Johannes, Saragnese, Marco, Schneider, Carsten
المصدر: Annals of mathematics and artificial intelligence 91(5), 591 - 649 (2023). doi:10.1007/s10472-023-09831-8
مصطلحات موضوعية: info:eu-repo/classification/ddc/004, differential equations, Feynman graph, structure, mathematical methods, Taylor expansion, topology, master integral, computer: algebra, numerical methods
جغرافية الموضوع: DE
الوصف: Hypergeometric structures in single and multiscale Feynman integrals emerge in a wide class of topologies. Using integration-by-parts relations, associated master or scalar integrals have to be calculated. For this purpose it appears useful to devise an automated method which recognizes the respective (partial) differential equations related to the corresponding higher transcendental functions. We solve these equations through associated recursions of the expansion coefficient of the multivalued formal Taylor series. The expansion coefficients can be determined using either the package {\tt Sigma} in the case of linear difference equations or by applying heuristic methods in the case of partial linear difference equations. In the present context a new type of sums occurs, the Hurwitz harmonic sums, and generalized versions of them. The code {\tt HypSeries} transforming classes of differential equations into analytic series expansions is described. Also partial difference equations having rational solutions and rational function solutions of Pochhammer symbols are considered, for which the code {\tt solvePartialLDE} is designed. Generalized hypergeometric functions, Appell-,~Kampé de Fériet-, Horn-, Lauricella-Saran-, Srivasta-, and Exton--type functions are considered. We illustrate the algorithms by examples.
العلاقة: info:eu-repo/semantics/altIdentifier/issn/1012-2443; info:eu-repo/semantics/altIdentifier/arxiv/arXiv:2111.15501; info:eu-repo/semantics/altIdentifier/issn/1573-7470; https://bib-pubdb1.desy.de/record/598863Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2023-07057%22Test
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7دورية أكاديمية
المؤلفون: Borinsky, Michael, Munch, Henrik J., Tellander, Felix
المصدر: Computer physics communications 292, 108874 (2023). doi:10.1016/j.cpc.2023.108874
مصطلحات موضوعية: info:eu-repo/classification/ddc/530, Feynman graph, numerical calculations, regularization: dimensional, kinematics, Feynman, causality, Monte Carlo, exceptional, Minkowski, propagator, computer, parametric, deformation, mathematical methods, Feynman integrals, Monte Carlo integration, Tropical geometry, Epsilon-expansion, Contour deformation, Causal i-epsilon prescription
جغرافية الموضوع: DE
الوصف: We present a new computer program, feyntrop, which uses the tropical geometric approach to evaluate Feynman integrals numerically. In order to apply this approach in the physical regime, we introduce a new parametric representation of Feynman integrals that implements the causal iε prescription concretely while retaining projective invariance. feyntrop can efficiently evaluate dimensionally regulated, quasi-finite Feynman integrals, with not too exceptional kinematics in the physical regime, with a relatively large number of propagators and with arbitrarily many kinematic scales. We give a systematic classification of all relevant kinematic regimes, review the necessary mathematical details of the tropical Monte Carlo approach, give fast algorithms to evaluate (deformed) Feynman integrands, describe the usage of feyntrop and discuss many explicit examples of evaluated Feynman integrals. Program title:feyntrop. CPC Library link to program files:https://doi.org/10.17632/k6r62hdgvd.1Test Developer's repository link:https://github.com/michibo/feyntropTest. Licensing provisions: MIT License. Programming language: The tropical Monte Carlo code is written in C++. The high-level interface is written in python. Supplementary material: The repository includes installation and usage instructions (README.md), a jupyter notebook tutorial (tutorial_2L_3pt.ipynb), the collection of examples presented in section 6 (see the folder /examples), and a test suite to ensure a successful installation (see the folder /tests). Nature of problem: Sufficiently fast numerical integration of (dimensionally regularized) Feynman integrals (also in the Minkowski regime of phase space). Solution method: Tropical Monte Carlo integration of a manifestly iε-free parametric representation of Feynman integrals. Additional comments: The program feyntrop is based on previous code available at https://github.com/michibo/tropicalTest-feynman-quadrature, which was published as a proof-of-concept with, Michael Borinsky, ‘Tropical Monte Carlo quadrature for Feynman ...
العلاقة: info:eu-repo/semantics/altIdentifier/issn/0010-4655; info:eu-repo/semantics/altIdentifier/arxiv/arXiv:2302.08955; info:eu-repo/semantics/altIdentifier/issn/1879-2944; info:eu-repo/semantics/altIdentifier/issn/1386-9485; https://bib-pubdb1.desy.de/record/597101Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2023-06430%22Test
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8مؤتمر
المؤلفون: Ramirez-Uribe, Selomit, Hernandez-Pinto, Roger, Renteria-Olivo, Andres, Rodrigo, German, Sborlini, German Fabricio Roberto, Torres Bobadilla, William, Vale Silva, Luiz
المصدر: Proceedings of Science / International School for Advanced Studies (EPS-HEP2021), 732 (2022). doi:10.22323/1.398.0732 ; The European Physical Society Conference on High-Energy Physics, EPS-HEP2021, Hamburg, Germany, 2021-07-26 - 2021-07-30
مصطلحات موضوعية: info:eu-repo/classification/ddc/530, topology, scattering amplitude, causality, duality, Feynman graph, loop integral: 4, singularity, mathematical methods
جغرافية الموضوع: DE
الوصف: In this document we present an overview of the analysis of the multiloop topologies that appear for the first time at four loops and the assembly of them in a general expression, the N$^4$MLT universal topology. Based on the fact that the LTD enables to open any scattering amplitude in terms of convolutions of known sub-topologies, we go through the dual representation of the universal N$^4$MLT topology and the explicit causal representations of selected configurations written in terms of entangled thresholds. Additionally, we expose the application of a quantum algorithm as an alternative to identify the causal singular configurations of the N$^4$MLT multiloop Feynman diagrams.
العلاقة: info:eu-repo/semantics/altIdentifier/issn/1824-8039; info:eu-repo/semantics/altIdentifier/arxiv/arXiv:2110.10605; https://bib-pubdb1.desy.de/record/465574Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2021-03962%22Test
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9مؤتمر
المؤلفون: Blümlein, Johannes, Saragnese, Marco, Schneider, Carsten
المصدر: Proceedings of Science / International School for Advanced Studies (LL2022), 041 (2022). doi:10.22323/1.416.0041 ; LL2022 Ettal, LL2022, Ettal, Germany, 2022-04-25 - 2022-04-30
مصطلحات موضوعية: info:eu-repo/classification/ddc/530, computer: algebra, Feynman graph, differential equations
جغرافية الموضوع: DE
الوصف: We present recent computer algebra methods that support the calculations of (multivariate) series solutions for (certain coupled systems of partial) linear differential equations. The summand of the series solutions may be built by hypergeometric products and more generally by indefinite nested sums defined over such products. Special cases are hypergeometric structures such as Appell-functions or generalizations of them that arise frequently when dealing with parameter Feynman integrals.
العلاقة: info:eu-repo/semantics/altIdentifier/issn/1824-8039; info:eu-repo/semantics/altIdentifier/arxiv/arXiv:2207.08524; https://bib-pubdb1.desy.de/record/480685Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2022-03936%22Test
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10دورية أكاديمية
المؤلفون: de la Cruz, Leonardo
المساهمون: Institut de Physique Théorique - UMR CNRS 3681 (IPHT), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
المصدر: Phys.Lett.B ; https://hal.science/hal-04557248Test ; Phys.Lett.B, 2024, 854, pp.138744. ⟨10.1016/j.physletb.2024.138744⟩
مصطلحات موضوعية: Feynman graph, loop integral: 3, geometry, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph]
الوصف: International audience ; Feynman integrals appropriately generalized are $\mathsf A$-hypergeometric functions. Among the properties of $\mathsf A$-hypergeometric functions are symmetries associated with the Newton polytope. In ordinary hypergeometric functions these symmetries lead to linear transformations. Combining tools of $\mathsf A$-hypergeometric systems and the computation of symmetries of polytopes, we consider the associated symmetries of Feynman integrals in the Lee-Pomeransky representation. We compute the symmetries of $\mathtt n$-gon integrals up to $\mathtt n=8$, massive banana integrals up to 5-loop, and on-shell ladders up to 3-loop. We apply these symmetries to study finite on-shell ladder integrals up to 3-loop.
العلاقة: info:eu-repo/semantics/altIdentifier/arxiv/2404.03564; hal-04557248; https://hal.science/hal-04557248Test; ARXIV: 2404.03564; INSPIRE: 2774089
