212 research outputs found
Derivation of the Cross-Free Family representation for the box diagram
I work out in full detail the derivation of the Cross-Free Family (CFF)
representation for the box diagram, and highlight the differences with its Time
Ordered Perturbation Theory (TOPT) representation. I briefly discuss
implications for the threshold singularity structure of the diagram.Comment: Proceedings for RADCOR 2023 - 16th International Symposium on
Radiative Corrections: Applications of Quantum Field Theory to Phenomenology,
Sunday 28th May 2023 - Friday 2nd June 2023, Crieff, Scotlan
Numerical Loop-Tree Duality: contour deformation and subtraction
We introduce a novel construction of a contour deformation within the
framework of Loop-Tree Duality for the numerical computation of loop integrals
featuring threshold singularities in momentum space. The functional form of our
contour deformation automatically satisfies all constraints without the need
for fine-tuning. We demonstrate that our construction is systematic and
efficient by applying it to more than 100 examples of finite scalar integrals
featuring up to six loops. We also showcase a first step towards handling
non-integrable singularities by applying our work to one-loop infrared
divergent scalar integrals and to the one-loop amplitude for the ordered
production of two and three photons. This requires the combination of our
contour deformation with local counterterms that regulate soft, collinear and
ultraviolet divergences. This work is an important step towards computing
higher-order corrections to relevant scattering cross-sections in a fully
numerical fashion.Comment: 87 page
A TAVOLA CON CHERUBINI. IL CANTIERE
Nel Vocabolario milanese italiano è presente non solo un ricchissimo vocabolario bilingue della cucina ma una vera e propria enciclopedia alimentare (prodotti, ingredienti, mestieri, piatti): un cantiere aperto e di enorme importanza per la storia della nostra cultura linguistica e gastronomica, sia prima dell’Unità sia dopo l’Unità d’Italia. Dining with Cherubini. A work in progressThe Vocabolario milanese italiano not only features a very rich range of terms regarding cooking but it is also a veritable encyclopedia of food (products, ingredients, professions, dishes): a work in progress of huge importance for the history of our culture, language and cuisine, both before and after the unification of Italy
Field Tests on Micropiles Under Dynamic Lateral Loading
Abstract Micropiles are increasingly used as foundation support of new buildings in seismic areas as well as for the seismic retrofitting of structures that have experienced seismic damage. Hence, it is essential to enhance the knowledge of the dynamic behavior of micropiles under horizontal loading. In the present paper, first steps of an extensive experimental study carried out on two vertical micropiles in alluvial silty soil are reported. One of the vertical micropiles is injected throughout valves a-manchettes placed along the steel core of the shaft, while the other one is simply grouted. In particular, experimental results of ambient vibration tests and impact load tests are reported and a comparison between the behavior of the vertical injected and non-injected micropiles is provided. Experimental data of impact load tests are also compared with results obtained from an analytical model
Loop Tree Duality for multi-loop numerical integration
Loop Tree Duality (LTD) offers a promising avenue to numerically integrate
multi-loop integrals directly in momentum space. It is well-established at one
loop, but there have been only sparse numerical results at two loops. We
provide a formal derivation for a novel multi-loop LTD expression and study its
threshold singularity structure. We apply our findings numerically to a diverse
set of up to four-loop finite topologies with kinematics for which no contour
deformation is needed. We also lay down the ground work for constructing such a
deformation. Our results serve as an important stepping stone towards a
generalised and efficient numerical implementation of LTD, applicable to the
computation of virtual corrections.Comment: 13 page
PHYSICAL ACTIVITY AND EXERCISE AS A KEY FACTOR IN SUCCESSFUL AGING
Aging is associated with several changes in body composition and metabolism, including sarcopenia, sarcopenic obesity and decrease in bone mass; aerobic capacity, muscle mass and strength tend to decline progressively. These changes have considerable impact on the ability to perform daily activities, especially when associated with chronic diseases, such as type 2 diabetes, cardio-vascular disease and dyslipidemia, as well as geriatric syndromes, like mobility impairment, falls and frailty. Scientific research has shown that physical activity and exercise can slow the physiological aging clock. Particularly, active elderly people seem to age "successfully" compared to sedentary ones. The aim of our work is to review evidence-based recommendations for physical activity, exercise and diet that would help to preserve muscle mass and strength, and to reduce the gain of fat mass in older adults. Increasing levels of physical activity, in particular resistance training mixed with aerobic exercise, and adequate protein nutrition intake should be an integral component in the prevention and treatment of sarcopenia, sarcopenic obesity and metabolic syndrome in elderly subjects
micropile foundation subjected to dynamic lateral loading
Abstract Thanks to their ease of installation, even in access-restricted spaces, micropiles are increasingly adopted for the seismic rehabilitation of existing structures. Moreover, both vertical and inclined micropiles are often used as foundation system for new constructions, ground improvements and many other applications. In order to deepen the knowledge of the dynamic behavior of those systems under horizontal loading, an extensive experimental study was carried out in an alluvial silty soil deposit on two single vertical micropiles and on a group of four inclined micropiles connected at the head by a concrete cap. Several testing procedures are exploited, in order to investigate the dynamic behavior of micropiles under different loading conditions and increasing force level, with special attention on the role of execution techniques and foundation configuration
Local Unitarity: a representation of differential cross-sections that is locally free of infrared singularities at any order
We propose a novel representation of differential scattering cross-sections
that locally realises the direct cancellation of infrared singularities
exhibited by its so-called real-emission and virtual degrees of freedom. We
take advantage of the Loop-Tree Duality representation of each individual
forward-scattering diagram and we prove that the ensuing expression is locally
free of infrared divergences, applies at any perturbative order and for any
process without initial-state collinear singularities. Divergences for loop
momenta with large magnitudes are regulated using local ultraviolet
counterterms that reproduce the usual Lagrangian renormalisation procedure of
quantum field theories. Our representation is especially suited for a numerical
implementation and we demonstrate its practical potential by computing fully
numerically and without any IR counterterm the next-to-leading order accurate
differential cross-section for the process . We
also show first results beyond next-to-leading order by computing interference
terms part of the N4LO-accurate inclusive cross-section of a
scalar scattering process.Comment: 88 page
Different Measuring Methods for Estimating the Hydraulic Conductivity on the Shallow Aquifer Along a Stretch of the Rimini Coast
Abstract The determination of hydraulic conductivity is a relevant topic for the characterization of widely-extended sandy coastal deposits. In the present work, the hydraulic conductivity of the Rimini Northern coastal deposits is evaluated through different procedures. Hydraulic conductivity is estimated from in situ and laboratory tests on small soil volumes, and from empirical correlations based on particle size distribution and in-situ tests. Relying on the variability ranges of the estimated parameters, a preliminary numerical water flow model of the testing area has been developed. Results can be considered as predictive of the hydraulic behavior of large soil volumes in the investigated area
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