scholarly journals Effective theories of coupled classical and quantum variables

2008 ◽  
pp. 153-168
Author(s):  
Jonathan J. Halliwell
Keyword(s):  
Effective Theories

scholarly journals Chern-Simons invariants and heterotic superpotentials

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Lara B. Anderson ◽  
James Gray ◽  
Andre Lukas ◽  
Juntao Wang
Keyword(s):  
Heterotic String ◽  
New Techniques ◽  
Vacuum Stability ◽  
Large Classes ◽  
Moduli Stabilization ◽  
String Compactifications ◽  
Key Features ◽  
Effective Theories ◽  
Chern Simons ◽  
Tangent Bundles

Abstract The superpotential in four-dimensional heterotic effective theories contains terms arising from holomorphic Chern-Simons invariants associated to the gauge and tangent bundles of the compactification geometry. These effects are crucial for a number of key features of the theory, including vacuum stability and moduli stabilization. Despite their importance, few tools exist in the literature to compute such effects in a given heterotic vacuum. In this work we present new techniques to explicitly determine holomorphic Chern-Simons invariants in heterotic string compactifications. The key technical ingredient in our computations are real bundle morphisms between the gauge and tangent bundles. We find that there are large classes of examples, beyond the standard embedding, where the Chern-Simons superpotential vanishes. We also provide explicit examples for non-flat bundles where it is non-vanishing and non-integer quantized, generalizing previous results for Wilson lines.

scholarly journals On-shell heavy particle effective theories

2020 ◽  
Vol 2020 (5) ◽  
Author(s):  
Rafael Aoude ◽  
Kays Haddad ◽  
Andreas Helset
Keyword(s):  
Heavy Particle ◽  
Effective Theories

scholarly journals Complex Langevin calculations in QCD at finite density

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Yuta Ito ◽  
Hideo Matsufuru ◽  
Yusuke Namekawa ◽  
Jun Nishimura ◽  
Shinji Shimasaki ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Chemical Potential ◽  
Expansion Method ◽  
Finite Density ◽  
Fermi Sphere ◽  
Expectation Value ◽  
Sign Problem ◽  
Zero Momentum ◽  
Effective Theories ◽  
Severe Sign

Abstract We demonstrate that the complex Langevin method (CLM) enables calculations in QCD at finite density in a parameter regime in which conventional methods, such as the density of states method and the Taylor expansion method, are not applicable due to the severe sign problem. Here we use the plaquette gauge action with β = 5.7 and four-flavor staggered fermions with degenerate quark mass ma = 0.01 and nonzero quark chemical potential μ. We confirm that a sufficient condition for correct convergence is satisfied for μ/T = 5.2 − 7.2 on a 83 × 16 lattice and μ/T = 1.6 − 9.6 on a 163 × 32 lattice. In particular, the expectation value of the quark number is found to have a plateau with respect to μ with the height of 24 for both lattices. This plateau can be understood from the Fermi distribution of quarks, and its height coincides with the degrees of freedom of a single quark with zero momentum, which is 3 (color) × 4 (flavor) × 2 (spin) = 24. Our results may be viewed as the first step towards the formation of the Fermi sphere, which plays a crucial role in color superconductivity conjectured from effective theories.

scholarly journals The Swampland Conjectures: A Bridge from Quantum Gravity to Particle Physics

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 273
Author(s):  
Mariana Graña ◽  
Alvaro Herráez
Keyword(s):  
Effective Field Theories ◽  
Quantum Gravity ◽  
Particle Physics ◽  
Effective Field ◽  
Low Energy ◽  
Field Theories ◽  
Neutrino Masses ◽  
Higgs Potential ◽  
Photon Mass ◽  
Effective Theories

The swampland is the set of seemingly consistent low-energy effective field theories that cannot be consistently coupled to quantum gravity. In this review we cover some of the conjectural properties that effective theories should possess in order not to fall in the swampland, and we give an overview of their main applications to particle physics. The latter include predictions on neutrino masses, bounds on the cosmological constant, the electroweak and QCD scales, the photon mass, the Higgs potential and some insights about supersymmetry.

scholarly journals Realization of brane descent relations in effective theories

2002 ◽  
Vol 66 (2) ◽  
Author(s):  
Koji Hashimoto ◽  
Satoshi Nagaoka
Keyword(s):  
Effective Theories

scholarly journals One-loop vertex integrals in heavy-particle effective theories

2002 ◽  
Vol 28 (6) ◽  
pp. 1179-1189 ◽  
Author(s):  
Antonio O Bouzas ◽  
Rub$eacute$n Flores-Mendieta
Keyword(s):  
Heavy Particle ◽  
Effective Theories

Renormalization group approach to quantum Hamiltonian dynamics

2015 ◽  
Vol 30 (09) ◽  
pp. 1530023 ◽  
Author(s):  
Stanisław D. Głazek
Keyword(s):  
Renormalization Group ◽  
Quantum Dynamics ◽  
Broad Class ◽  
Hamiltonian Dynamics ◽  
Group Approach ◽  
Physical Problems ◽  
Minkowski Space Time ◽  
Renormalization Group Approach ◽  
Effective Theories ◽  
Dynamics Of Particles

Ken Wilson developed powerful renormalization group procedures for constructing effective theories and solving a broad class of difficult physical problems. His insights allowed him to later advance the Hamiltonian approach to quantum dynamics of particles and fields in the Minkowski space–time, motivated by QCD. The latter advances are described in this article, concluding with a remark on Ken's related interest in difficult systemic issues of society.

scholarly journals Early Universe effective theories: the soft leptogenesis and R-genesis cases

2011 ◽  
Vol 2011 (02) ◽  
pp. 032-032 ◽  
Author(s):  
Chee Sheng Fong ◽  
M.C Gonzalez-Garcia ◽  
Enrico Nardi
Keyword(s):  
Early Universe ◽  
Effective Theories

Mechanical Patterning in Animal Morphogenesis

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Yonit Maroudas-Sacks ◽  
Kinneret Keren
Keyword(s):  
Pattern Formation ◽  
Large Scale ◽  
Coarse Grained ◽  
Annual Review ◽  
Publication Date ◽  
Biochemical Processes ◽  
Substantial Progress ◽  
Biological Pattern Formation ◽  
Effective Theories ◽  
Biochemical Signals

Morphogenesis is one of the most remarkable examples of biological pattern formation. Despite substantial progress in the field, we still do not understand the organizational principles responsible for the robust convergence of the morphogenesis process across scales to form viable organisms under variable conditions. Achieving large-scale coordination requires feedback between mechanical and biochemical processes, spanning all levels of organization and relating the emerging patterns with the mechanisms driving their formation. In this review, we highlight the role of mechanics in the patterning process, emphasizing the active and synergistic manner in which mechanical processes participate in developmental patterning rather than merely following a program set by biochemical signals. We discuss the value of applying a coarse-grained approach toward understanding this complex interplay, which considers the large-scale dynamics and feedback as well as complementing the reductionist approach focused on molecular detail. A central challenge in this approach is identifying relevant coarse-grained variables and developing effective theories that can serve as a basis for an integrated framework for understanding this remarkable pattern-formation process. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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