<div dir="ltr"><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small;color:#333333"><span style="background-color:transparent">Fwiw, where I&#39;m at...<br><br></span><a href="https://www.youtube.com/watch?v=gI0DYD2FhtE">https://www.youtube.com/watch?v=gI0DYD2FhtE</a><br><br><span style="background-color:transparent"></span></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small;color:#333333">or probably more accurately:<br><br><a href="https://www.stat.uchicago.edu/~lekheng/work/psapm.pdf">https://www.stat.uchicago.edu/~lekheng/work/psapm.pdf</a></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small;color:#333333"><br></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small;color:#333333"><a href="https://www.math.stonybrook.edu/~bishop/classes/math638.F20/Canzani_Laplacian_Notes.pdf">https://www.math.stonybrook.edu/~bishop/classes/math638.F20/Canzani_Laplacian_Notes.pdf</a></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small;color:#333333"><br></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small;color:#333333">Except, not in the domain of physics of course. Some on list may have done the work before (or recently) of recovering proper geometry from what otherwise is a dearth of isospectral properties. I would love to know who out there might be worth having a discussion with regarding such techniques, limitations and frontiers.</div></div>