| Records |
| Author |
Ramirez-Uribe, S.; Hernandez-Pinto, R.J.; Rodrigo, G.; Sborlini, G.F.R. |
| Title |
From Five-Loop Scattering Amplitudes to Open Trees with the Loop-Tree Duality |
Type |
Journal Article |
| Year |
2022 |
Publication  |
Symmetry-Basel |
Abbreviated Journal |
Symmetry-Basel |
| Volume |
14 |
Issue |
12 |
Pages |
2571 - 14pp |
| Keywords |
perturbative QFT; higher-order calculations; multiloop Feynman integrals |
| Abstract |
Characterizing multiloop topologies is an important step towards developing novel methods at high perturbative orders in quantum field theory. In this article, we exploit the Loop-Tree Duality (LTD) formalism to analyse multiloop topologies that appear for the first time at five loops. Explicitly, we open the loops into connected trees and group them according to their topological properties. Then, we identify a kernel generator, the so-called N7MLT universal topology, that allows us to describe any scattering amplitude of up to five loops. Furthermore, we provide factorization and recursion relations that enable us to write these multiloop topologies in terms of simpler subtopologies, including several subsets of Feynman diagrams with an arbitrary number of loops. Our approach takes advantage of many symmetries present in the graphical description of the original fundamental five-loop topologies. The results obtained in this article might shed light into a more efficient determination of higher-order corrections to the running couplings, which are crucial in the current and future precision physics program. |
| Address |
[Ramirez-Uribe, Selomit; Rodrigo, German] Univ Valencia, Inst Fis Corpuscular, Consejo Super Invest Cient, Parc Cient, E-46980 Paterna, Spain, Email: roger@uas.edu.mx |
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| Publisher |
Mdpi |
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| Language |
English |
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Conference |
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| Notes |
WOS:000904374000001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5450 |
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| Author |
Van Isacker, P.; Algora, A.; Vitéz-Sveiczer, A.; Kiss, G.G.; Orrigo, S.E.A.; Rubio, B.; Aguilera, P. |
| Title |
Gamow-Teller Beta Decay and Pseudo-SU(4) Symmetry |
Type |
Journal Article |
| Year |
2023 |
Publication |
Symmetry-Basel |
Abbreviated Journal |
Symmetry-Basel |
| Volume |
15 |
Issue |
11 |
Pages |
2001 - 15pp |
| Keywords |
Gamow-Teller beta decay; pseudo-SU(4) symmetry; odd-odd N = Z nuclei |
| Abstract |
We report on recent experimental results on beta decay into self-conjugate ( N = Z) nuclei with mass number 58 <= A <= 70. Super-allowed b decays from the J(pi) = 0(+) ground state of a Z = N + 2 parent nucleus are to the isobaric analogue state through so-called Fermi transitions and to J(pi) = 1(+) states by way of Gamow-Teller (GT) transitions. The operator of the latter decay is a generator of Wigner's SU(4) algebra and as a consequence GT transitions obey selection rules associated with this symmetry. Since SU(4) is progressively broken with increasing A, mainly as a consequence of the spinorbit interaction, this symmetry is not relevant for the nuclei considered here. We argue, however, that the pseudo-spin-orbit splitting can be small in nuclei with 58 <= A <= 70, in which case nuclear states exhibit an approximate pseudo-SU(4) symmetry. To test this conjecture, GT decay strength is calculated with use of a schematic Hamiltonian with pseudo-SU(4) symmetry. Some generic features of the GT beta decay due to pseudo-SU(4) symmetry are pointed out. The experimentally observed GT strength indicates a restoration of pseudo-SU(4) symmetry for A = 70. |
| Address |
[Van Isacker, Piet] CEA, DRF, Grand Accelerateur Natl Ions Lourds GANIL, CNRS,IN2P3, Blvd Henri Becquerel, F-14076 Caen, France, Email: isacker@ganil.fr; |
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| Publisher |
Mdpi |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001114520800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5843 |
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| Author |
Aldana, M.; Lledo, M.A. |
| Title |
The Fuzzy Bit |
Type |
Journal Article |
| Year |
2023 |
Publication |
Symmetry-Basel |
Abbreviated Journal |
Symmetry-Basel |
| Volume |
15 |
Issue |
12 |
Pages |
2103 - 25pp |
| Keywords |
fuzzy sets; quantum logic; multivalued logic; Quantum Mechanics |
| Abstract |
In this paper, the formulation of Quantum Mechanics in terms of fuzzy logic and fuzzy sets is explored. A result by Pykacz, which establishes a correspondence between (quantum) logics (lattices with certain properties) and certain families of fuzzy sets, is applied to the Birkhoff-von Neumann logic, the lattice of projectors of a Hilbert space. Three cases are considered: the qubit, two qubits entangled, and a qutrit 'nested' inside the two entangled qubits. The membership functions of the fuzzy sets are explicitly computed and all the connectives of the fuzzy sets are interpreted as operations with these particular membership functions. In this way, a complete picture of the standard quantum logic in terms of fuzzy sets is obtained for the systems considered. |
| Address |
[Aldana, Milagrosa] Univ Simon Bolivar, Dept Ciencias Tierra, Valle De Sartenejas 89000, Baruta, Venezuela, Email: maldana@usb.ve; |
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| Publisher |
Mdpi |
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| Language |
English |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001131238400001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5962 |
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| Author |
Borja, E.F.; Garay, I.; Vidotto, F. |
| Title |
Learning about Quantum Gravity with a Couple of Nodes |
Type |
Journal Article |
| Year |
2012 |
Publication |
Symmetry Integrability and Geometry-Methods and Applications |
Abbreviated Journal |
Symmetry Integr. Geom. |
| Volume |
8 |
Issue |
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Pages |
015 - 44pp |
| Keywords |
discrete gravity; canonical quantization; spinors; spinfoam; quantum cosmology |
| Abstract |
Loop Quantum Gravity provides a natural truncation of the infinite degrees of freedom of gravity, obtained by studying the theory on a given finite graph. We review this procedure and we present the construction of the canonical theory on a simple graph, formed by only two nodes. We review the U(N) framework, which provides a powerful tool for the canonical study of this model, and a formulation of the system based on spinors. We consider also the covariant theory, which permits to derive the model from a more complex formulation, paying special attention to the cosmological interpretation of the theory. |
| Address |
[Borja, Enrique F.; Garay, Inaki] Univ Erlangen Nurnberg, Inst Theoret Phys 3, D-91058 Erlangen, Germany, Email: efborja@theorie3.physik.uni-erlangen.de; |
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Natl Acad Sci Ukraine, Inst Math |
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English |
Summary Language |
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Edition |
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1815-0659 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
WOS:000303831400001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1018 |
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| Author |
Aliaga, R.J.; Guirao, A.J. |
| Title |
On the preserved extremal structure of Lipschitz-free spaces |
Type |
Journal Article |
| Year |
2019 |
Publication |
Studia Mathematica |
Abbreviated Journal |
Studia Math. |
| Volume |
245 |
Issue |
1 |
Pages |
1-14 |
| Keywords |
concave space; extremal structure; Lipschitz-free space; Lipschitz function; metric alignment; preserved extreme point |
| Abstract |
We characterize preserved extreme points of the unit ball of Lipschitz-free spaces F (X) in terms of simple geometric conditions on the underlying metric space (X, d). Namely, the preserved extreme points are the elementary molecules corresponding to pairs of points p, q in X such that the triangle inequality d (p, q) <= d (p, r) + d (q, r) is uniformly strict for r away from p, q. For compact X, this condition reduces to the triangle inequality being strict. As a consequence, we give an affirmative answer to a conjecture of N. Weaver that compact spaces are concave if and only if they have no triple of metrically aligned points, and we show that all extreme points are preserved for several classes of compact metric spaces X, including Holder and countable compacta. |
| Address |
[Aliaga, Ramon J.; Guirao, Antonio J.] Univ Politecn Valencia, Inst Univ Matemat Pura & Aplicada, Camino Vera S-N, E-46022 Valencia, Spain, Email: raalva@upvnet.upv.es; |
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Polish Acad Sciences Inst Mathematics-Impan |
Place of Publication |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0039-3223 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000446980500001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
3753 |
| Permanent link to this record |
