scholarly journals The Role of Scalar Mesons in Extended Perturbation Scheme for Effective Field Theory

2008 ◽  
Author(s):  
Kirill Semenov-Tian-Shansky ◽  
Alexander Vereshagin ◽  
Vladimir Vereshagin ◽  
George Rupp ◽  
Eef van Beveren ◽  
...  
2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Arjun Berera ◽  
Suddhasattwa Brahma ◽  
Jaime R. Calderón

Abstract Motivated by the old trans-Planckian (TP) problem of inflationary cosmology, it has been conjectured that any consistent effective field theory should keep TP modes ‘hidden’ behind the Hubble horizon, so as to prevent them from turning classical and thereby affecting macroscopic observations. In this paper we present two arguments against the Hubble horizon being a scale of singular significance as has been put forward in the TP Censorship Conjecture (TCC). First, refinements of TCC are presented that allow for the TP modes to grow beyond the horizon while still keeping the de-Sitter conjecture valid. Second, we show that TP modes can turn classical even well within the Hubble horizon, which, as such, negates this rationale behind keeping them from crossing it. The role of TP modes is known to be less of a problem in warm inflation, because fluctuations start out usually as classical. This allows warm inflation to be more resilient to the TP problem compared to cold inflation. To understand how robust this is, we identity limits where quantum modes can affect the primordial power spectrum in one specific case.


2019 ◽  
Vol 99 (12) ◽  
Author(s):  
Joshua Eby ◽  
Kyohei Mukaida ◽  
Masahiro Takimoto ◽  
L. C. R. Wijewardhana ◽  
Masaki Yamada

2014 ◽  
Vol 29 (26) ◽  
pp. 1430052 ◽  
Author(s):  
Walter Dittrich

We review the beginning of the effective Lagrangian in QED that was first introduced in the literature by W. Heisenberg and H. Euler in 1936. Deviating from their way of calculating the one-loop effective correction to the classical Maxwell Lagrangian, we use Green's functions and adopt the Fock–Schwinger proper-time method. The important role of the Heisenberg–Euler effective Lagrangian is explicitly demonstrated for low-energy photon–photon processes.


2014 ◽  
Vol 26 ◽  
pp. 1460088
Author(s):  
J. M. ALARCÓN

We stress, on theoretical and phenomenological grounds, the importance of the Δ(1232)-resonance in a chiral effective field theory approach to the study of πN scattering. We show how its inclusion as a dynamical degree of freedom allow us to obtain reliably valuable information from πN scattering data.


2011 ◽  
Vol 26 (03n04) ◽  
pp. 353-358
Author(s):  
CHRISTOPH HANHART

In recent years a large number of new states in the charm sector was discovered above the first inelastic threshold that not at all match to the predictions of the quark model, which on the other hand was extremely successful below that threshold. Since most of those states are located close to a two–hadron threshold, many authors proposed a molecular nature for them. In this talk we will collect the evidences and discuss how the picture can be tested further. In addition, if hadron loops induce non-perturbative effects above the inelastic threshold, one should also expect them to have some impact on the properties of standard charmonia. In the last part of this write-up an effective field theory is introduced that allows one to investigate this issue systematically.


Author(s):  
Ervin Goldfain

The goal of this work is to show that the underlying symmetries of effective field theory can be traced to the onset of self-similarity. In particular, we argue that the scale-free structure of fractal geometry lies at the heart of invariance principles in classical and Quantum Field Theory.


2008 ◽  
Vol 659 (1-2) ◽  
pp. 184-191 ◽  
Author(s):  
V. Baru ◽  
J. Haidenbauer ◽  
C. Hanhart ◽  
A. Kudryavtsev ◽  
V. Lensky ◽  
...  

2016 ◽  
Vol 25 (05) ◽  
pp. 1641010 ◽  
Author(s):  
Dean Lee

We discuss the theory and computational algorithms involved in nuclear lattice simulations using chiral effective field theory. We elucidate the role of Wigner’s SU(4) symmetry and the role it plays in alpha clustering and rendering the auxiliary-field projection Monte Carlo simulations tractable.


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