Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Routh-Hurwitz Criterion II

Routh-Hurwitz Criterion II

In the application of the Routh-Hurwitz criterion, two specific scenarios can arise that complicate stability analysis.
The first scenario occurs when a singular zero appears in the first column of the Routh table. This situation creates a division by zero issues. To resolve this, a small positive or negative number, denoted as epsilon (∈), is substituted for the zero. The stability analysis proceeds by assuming a sign for ∈. If ∈ is positive, any sign change in the first column of the Routh...

Shunt Admittances

Shunt Admittances

Shunt admittances play a crucial role in the analysis of transmission lines, particularly for three-phase systems with neutral conductors. When a uniformly charged conductor is positioned above the Earth, it induces an equal but opposite charge on its surface. This interaction creates electric field lines between the conductor and the Earth.
To model this effect, the method of images is employed. This method involves replacing the Earth with an image conductor that mirrors the original...

Routh-Hurwitz Criterion I

Routh-Hurwitz Criterion I

Consider an electrical power grid, where stability is essential to prevent blackouts. The Routh-Hurwitz criterion is a valuable tool for assessing system stability under varying load conditions or faults. By analyzing the closed-loop transfer function, the Routh-Hurwitz criterion helps determine whether the system remains stable.
To apply the Routh-Hurwitz criterion, a Routh table is constructed. The table's rows are labeled with powers of the complex frequency variable s, starting from the...

The Power Flow Problem and Solution

The Power Flow Problem and Solution

Power flow problem analysis is fundamental for determining real and reactive power flows in network components, such as transmission lines, transformers, and loads. The power system's single-line diagram provides data on the bus, transmission line, and transformer. Each bus k in the system is characterized by four key variables: voltage magnitude Vk, phase angle δk, real power Pk, and reactive power Qk. Two of these four variables are inputs, while the power flow program computes the...

Thermal Sigmatropic Reactions: Overview

Thermal Sigmatropic Reactions: Overview

Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i,&VeryThinSpace;j&VeryThinSpace;], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred to as...

Linear Approximation in Time Domain

Linear Approximation in Time Domain

Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs.
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Indications against Dynamical CPT Symmetry Restoration in Quantum Gravity.

Physical review letters·2026

Same author

3D quantum gravity and effective noncommutative quantum field theory.

Physical review letters·2006

See all related articles

Search research articles

Related Experiment Video

Updated: Jul 12, 2026

Setting Limits on Supersymmetry Using Simplified Models

Setting Limits on Supersymmetry Using Simplified Models

Published on: November 15, 2013

Nonperturbative S-Matrix Renormalization.

Laurent Freidel¹, José Padua-Argüelles^1,2, Susanne Schander¹

¹Perimeter Institute, 31 Caroline Street North, Waterloo, Ontario, N2L 2Y5, Canada.

Physical Review Letters

|July 10, 2026

Summary

We introduce a new renormalization group flow equation that directly generates scattering amplitudes, simplifying calculations in nonperturbative quantum field theories. This method offers advantages over existing equations by focusing on observables and avoiding complex mathematical inversions.

Related Experiment Videos

Last Updated: Jul 12, 2026

Setting Limits on Supersymmetry Using Simplified Models

Setting Limits on Supersymmetry Using Simplified Models

Published on: November 15, 2013

Area of Science:

Theoretical Physics
Quantum Field Theory

Background:

The Wetterich and Polchinski equations are established methods for quantum field theory calculations.
These methods involve off-shell objects like the effective action and Schwinger functional.
Calculating scattering amplitudes directly is often complex.

Purpose of the Study:

To propose a novel renormalization group flow equation.
To develop a method that works more directly with observables, specifically scattering amplitudes.
To simplify the process of satisfying quantum equations of motion.

Main Methods:

Development of a new renormalization group flow equation.
Focus on a functional that generates S-matrix elements.
Comparison with existing Wetterich and Polchinski equations.

Main Results:

The proposed flow equation generates S-matrix elements directly.
It simplifies the process of satisfying quantum equations of motion (going on shell).
The equation is polynomial and avoids Hessian inversion, unlike the Wetterich equation.

Conclusions:

The new flow equation offers a promising direction for nonperturbative quantum field theories.
It provides a more direct approach to calculating scattering amplitudes.
This method simplifies theoretical calculations by focusing on observables.