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Related papers: Effective Lagrangians in $2 + \epsilon$ Dimensions

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Functional methods can be applied to the quantum effective action to efficiently determine counterterms and matching conditions for effective field theories. We extend the toolbox to two-loop order and beyond and show how to evaluate the…

High Energy Physics - Phenomenology · Physics 2025-08-20 Javier Fuentes-Martín , Adrián Moreno-Sánchez , Ajdin Palavrić , Anders Eller Thomsen

We give conditions on a real-valued function $F$ on $\mathbb{Z}^d$, for $d>2$, which ensure that the solution $G$ to the convolution equation $(F*G)(x) = \delta_{0,x}$ has Gaussian decay $|x|^{-(d-2)}$ for large $|x|$. Precursors of our…

Probability · Mathematics 2025-02-04 Yucheng Liu , Gordon Slade

We prove $|x|^{-2}$ decay of the critical two-point function for the continuous-time weakly self-avoiding walk on $\mathbb{Z}^d$, in the upper critical dimension $d=4$. This is a statement that the critical exponent $\eta$ exists and is…

Mathematical Physics · Physics 2015-11-05 Roland Bauerschmidt , David C. Brydges , Gordon Slade

The low-energy and low-momentum dynamics of systems with a spontaneously broken continuous symmetry is dominated by the ensuing Nambu-Goldstone bosons. It can be conveniently encoded in a model-independent effective field theory whose…

High Energy Physics - Phenomenology · Physics 2014-08-19 Jens O. Andersen , Tomas Brauner , Christoph P. Hofmann , Aleksi Vuorinen

We extend an effective Lagrangian embodying broken scale and chiral symmetry to include explicit chiral symmetry breaking and an additional chiral invariant term which allows for an axial coupling constant greater than unity. We also…

Nuclear Theory · Physics 2009-10-28 G. Carter , P. J. Ellis , S. Rudaz

We discuss general one and two-loop banana diagrams and one-loop diagrams with external lines with arbitrary masses on the anti de Sitter spacetime by using methods of AdS quantum field theory in the dimensional regularization approach. The…

High Energy Physics - Theory · Physics 2024-06-25 Sergio L. Cacciatori , Henri Epstein , Ugo Moschella

This letter is an investigation of the pion form factor utilizing recently developed effective field theory techniques. The primary results reported are: Both the transition and electromagnetic form factors are corrected at order…

High Energy Physics - Phenomenology · Physics 2009-11-10 Ira Z. Rothstein

We construct the minimal effective chiral pion-nucleon SU(2) Lagrangian at fourth order in the chiral expansion. The Lagrangian contains 118 in principle measurable terms. We develop both the relativistic as well as the heavy baryon…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nadia Fettes , Ulf-G. Meißner , Martin Mojzis , Sven Steininger

We construct effective Lagrangians of the Veneziano-Yankielowicz (VY) type for two non-supersymmetric theories which are orientifold daughters of supersymmetric gluodynamics (containing one Dirac fermion in the two-index antisymmetric or…

High Energy Physics - Theory · Physics 2009-11-10 F. Sannino , M. Shifman

In this paper, we derive suitable optimal $L^p-L^q$ decay estimates, $1\leq p\leq q\leq \infty$, for the solutions to the $\sigma$-evolution equation, $\sigma>1$, with structural damping and power nonlinearity $|u|^{1+\alpha}$ or…

Analysis of PDEs · Mathematics 2022-02-11 Marcello D'Abbicco , Marcelo Rempel Ebert

In order to investigate specific aspects of bound state calculations in a non-relativistic framework, we consider the energy-levels of a massive scalar particle, which moves in an external field and interacts in addition with a massless…

High Energy Physics - Phenomenology · Physics 2009-10-31 V. Antonelli , A. Gall , J. Gasser , A. Rusetsky

We introduce a Lagrangian-space Effective Field Theory (LEFT) formalism for the study of cosmological large scale structures. Unlike the previous Eulerian-space construction, it is naturally formulated as an effective field theory of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Rafael A. Porto , Leonardo Senatore , Matias Zaldarriaga

The logarithmic Laplacian on the (whole) N-dimensional Euclidean space is defined as the first variation of the fractional Laplacian of order 2s at s=0 or, alternatively, as a singular Fourier integral operator with logarithmic symbol.…

Analysis of PDEs · Mathematics 2023-12-27 Huyuan Chen , Daniel Hauer , Tobias Weth

Maintaining the preserved supersymmetry helps to find the effective Lagrangian on the BPS background in gauge theories with eight supercharges. As concrete examples, we take 1/2 BPS domain walls. The Lagrangian is given in terms of the…

High Energy Physics - Theory · Physics 2008-11-26 Norisuke Sakai , Minoru Eto , Youichi Isozumi , Muneto Nitta , Keisuke Ohashi

In this talk the $Q$ counting scheme to implement effective field theory is discussed. It is pointed out that there are two small mass scales in the problem $m_\pi$ and $1/a$ with $1/a \ll m_\pi$. It is argued that while the expansion based…

Nuclear Theory · Physics 2007-05-23 Thomas D. Cohen

We derive the mass correction lagrangian of the heavy meson effective theory by using the projection operator method. The next leading order of the mass correction and the first order of the chiral expansion are given explicitely.We also…

High Energy Physics - Phenomenology · Physics 2016-09-01 Tsung-Wen Yeh , Chien-er Lee

Dimensional correspondences have a long history in critical phenomena. Here, we review the effective dimension approach, which relates the scaling exponents of a critical system in $d$ spatial dimensions with power-law decaying interactions…

Statistical Mechanics · Physics 2024-12-17 Andrea Solfanelli , Nicolò Defenu

We develop the concept and the calculus of anti-self dual (ASD) Lagrangians which seems inherent to many questions in mathematical physics, geometry, and differential equations. They are natural extensions of gradients of convex functions…

Analysis of PDEs · Mathematics 2007-05-23 Nassif Ghoussoub

We consider oscillons - localized, quasiperiodic, and extremely long-living classical solutions in models with real scalar fields. We develop their effective description in the limit of large size at finite field strength. Namely, we note…

High Energy Physics - Theory · Physics 2022-12-19 D. G. Levkov , V. E. Maslov , E. Ya. Nugaev , A. G. Panin

We analyze the structure of multiloop supergraphs contributing to the effective Lagrangians in 4d supersymmetric gauge theories and in the models obtained from them by dimensional reduction. When d=4, this gives the renormalization of the…

High Energy Physics - Theory · Physics 2008-11-26 Andrei Smilga , Arkady Vainshtein