Linear response laws and causality in electrodynamics

Autor:	John A. Scales, Alex J. Yuffa
Rok vydání:	2012
Předmět:	Physics Source function General Physics and Astronomy Context (language use) law.invention Causality (physics) symbols.namesake Theoretical physics Fourier transform Maxwell's equations Law Frequency domain CLARITY symbols Classical electromagnetism
Zdroj:	European Journal of Physics. 33:1635-1650
ISSN:	1361-6404 0143-0807
DOI:	10.1088/0143-0807/33/6/1635
Popis:	Linear response laws and causality (the effect cannot precede the cause) are of fundamental importance in physics. In the context of classical electrodynamics, students often have a difficult time grasping these concepts because the physics is obscured by the intermingling of the time and frequency domains. In this paper, we analyse the linear response laws and causality in the time and frequency domains with the aim of pedagogical clarity. We will show that it is easy to violate causality in the frequency domain by making a vanishing absorption approximation. Furthermore, we will show that there can be subtle differences between Fourier transforming Maxwell equations and using a monochromatic source function. We discuss how these concepts can be obscured and offer some suggestions to improve the situation.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::0694f8d93d499113392c849f9470d5ce https://doi.org/10.1088/0143-0807/33/6/1635 Zobrazit plný text záznamu