Gauge Invariance Approach to Acoustic Fields

Download or read book Gauge Invariance Approach to Acoustic Fields written by Woon Siong Gan and published by Springer. This book was released on 2019-07-31 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the symmetry properties of acoustic fields and describes the gauge invariance approach, which can be used to reveal those properties. Symmetry is the key theoretical framework of metamaterials, as has been demonstrated by the successful fabrication of acoustical metamaterials. The book first provides the necessary theoretical background, which includes the covariant derivative, the vector potential, and invariance in coordinate transformation. This is followed by descriptions of global gauge invariance (isotropy), and of local gauge invariance (anisotropy). Sections on time reversal symmetry, reflection invariance, and invariance of finite amplitude waves round out the coverage.