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Related papers: Local renormalisation from causal loop-tree dualit…

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We review the recent developments of the loop-tree duality method, focussing our discussion on analysing the singular behaviour of the loop integrand of the dual representation of one-loop integrals and scattering amplitudes. We show that…

High Energy Physics - Phenomenology · Physics 2014-07-23 Sebastian Buchta , Grigorios Chachamis , Ioannis Malamos , Isabella Bierenbaum , Petros Draggiotis , German Rodrigo

Using loop-tree duality, we relate a renormalised $n$-point $l$-loop amplitude in a quantum field theory to a phase-space integral of a regularised $l$-fold forward limit of a UV-subtracted $(n+2l)$-point tree-amplitude-like object. We show…

High Energy Physics - Phenomenology · Physics 2020-07-01 Robert Runkel , Zoltán Szőr , Juan Pablo Vesga , Stefan Weinzierl

Understanding the cancellation of ultraviolet and infrared singularities in perturbative quantum field theory is of central importance for the development and automation of various theoretical tools that make accurate predictions for…

High Energy Physics - Theory · Physics 2024-11-11 David F. Rentería-Estrada

Though the one-loop amplitudes of the Higgs boson to massless gauge bosons are finite because there is no direct interaction at tree-level in the Standard Model, a well-defined regularization scheme is still required for their correct…

High Energy Physics - Phenomenology · Physics 2018-03-22 Felix Driencourt-Mangin , German Rodrigo , German F. R. Sborlini

The numerical evaluation of multi-loop scattering amplitudes in the Feynman representation usually requires to deal with both physical (causal) and unphysical (non-causal) singularities. The loop-tree duality (LTD) offers a powerful…

A perturbative description of Large Scale Structure is a cornerstone of our understanding of the observed distribution of matter in the universe. Renormalization is an essential and defining step to make this description physical and…

High Energy Physics - Theory · Physics 2016-06-08 Ali Akbar Abolhasani , Mehrdad Mirbabayi , Enrico Pajer

Within the Local Unitarity formalism, any physical cross-section is re-written in such a way that cancellations of infrared singularities between real and virtual contributions are realised locally. Consequently, phase-space and loop…

High Energy Physics - Phenomenology · Physics 2021-11-01 Zeno Capatti

In the past years, we have been developing a novel technique, called Four-Dimensional Unsubtraction (FDU) which aims to obtain purely four-dimensional representations of the matrix elements contributing to physical observables. In this…

High Energy Physics - Phenomenology · Physics 2019-11-05 German F. R. Sborlini

The loop-tree duality (LTD) has become a novelty alternative to bootstrap the numerical evaluation of multi-loop scattering amplitudes. It has indeed been found that Feynman integrands, after the application of LTD, display a representation…

High Energy Physics - Phenomenology · Physics 2021-10-29 William J. Torres Bobadilla

In this talk, we review the basis of the loop-tree duality theorem, which allows to rewrite loop scattering amplitudes in terms of tree-level like objects. Since the loop measure is converted into a phase-space one, both virtual and real…

High Energy Physics - Phenomenology · Physics 2016-11-16 German F. R. Sborlini , Felix Driencourt-Mangin , Roger Hernandez-Pinto , German Rodrigo

Multi-loop scattering amplitudes constitute a serious bottleneck in current high-energy physics computations. Obtaining new integrand level representations with smooth behaviour is crucial for solving this issue, and surpassing the…

High Energy Physics - Phenomenology · Physics 2021-09-17 German F. R. Sborlini

In this talk, we review the most recent developments of the four-dimensional unsubstraction (FDU) and loop-tree duality (LTD) methods. In particular, we make emphasis on the advantages of the LTD formalism regarding asymptotic expansions of…

High Energy Physics - Phenomenology · Physics 2018-01-16 German Rodrigo , Felix Driencourt-Mangin , German F. R. Sborlini , Roger J. Hernandez-Pinto

Unveiling hidden symmetries within Feynman diagrams is crucial for achieving more efficient computations in high-energy physics. In this paper, we study the symmetries underlying the causal Loop-Tree Duality (LTD) representations through a…

High Energy Physics - Theory · Physics 2025-05-12 Irene Lopez Imaz , German Sborlini

Loop-tree duality allows to express virtual contributions in terms of phase-space integrals, thus leading to a direct comparison with real radiation terms. In this talk, we review the basis of the method and describe its application to…

High Energy Physics - Phenomenology · Physics 2016-01-21 German F. R. Sborlini

We extend the four-dimensional unsubtraction method, which is based on the loop-tree duality (LTD), to deal with processes involving heavy particles. The method allows to perform the summation over degenerate IR configurations directly at…

High Energy Physics - Phenomenology · Physics 2016-11-23 German F. R. Sborlini , Felix Driencourt-Mangin , German Rodrigo

The causal representation of multi-loop scattering amplitudes, obtained from the application of the loop-tree duality formalism, comprehensively elucidates, at integrand level, the behaviour of only physical singularities. This…

High Energy Physics - Phenomenology · Physics 2021-06-23 William J. Torres Bobadilla

We present a new method to compute higher-order corrections to physical cross-sections, at Next-to-Leading Order and beyond. This method, based on the Loop Tree Duality, leads to locally integrable expressions in four dimensions. By…

High Energy Physics - Phenomenology · Physics 2017-04-05 Felix Driencourt-Mangin

We present a first numerical implementation of the Loop-Tree Duality (LTD) method for the direct numerical computation of multi-leg one-loop Feynman integrals. We discuss in detail the singular structure of the dual integrands and define a…

High Energy Physics - Phenomenology · Physics 2015-10-06 Sebastian Buchta , Grigorios Chachamis , Petros Draggiotis , German Rodrigo

The Loop-Tree Duality (LTD) is a novel perturbative method in QFT that establishes a relation between loop-level and tree-level amplitudes, which gives rise to the idea of treating them simultaneously in a common Monte Carlo. Initially…

High Energy Physics - Phenomenology · Physics 2015-10-15 Sebastian Buchta

In this work, we extend the dual triply irreducible local expansion (D-TRILEX) approach for correlated electronic systems by introducing a cluster reference system for the diagrammatic expansion. This framework allows us to consistently…

Strongly Correlated Electrons · Physics 2026-02-26 Félix Fossati , Evgeny A. Stepanov