COOKIES: By using this website you agree that we can place Google Analytics Cookies on your device for performance monitoring. |

University of Cambridge > Talks.cam > Isaac Newton Institute Seminar Series > Quadratic spectral concentration of characteristic functions

## Quadratic spectral concentration of characteristic functionsAdd to your list(s) Download to your calendar using vCal - Kristina Oganesyan (Universitat Autònoma de Barcelona)
- Tuesday 16 July 2024, 12:15-12:35
- Seminar Room 1, Newton Institute.
If you have a question about this talk, please contact nobody. DREW01 - Multivariate approximation, discretization, and sampling recovery A theorem of Donoho and Stark states that decreasing rearrangement increases the quadratic spectral concentration of a square integrable function supported on a sufficiently small set. Importantly, their condition on the smallness of the support turns out to be necessary. In this talk, we restrict ourselves to considering only characeristic functions and, in this setting, we are able to relax the condition of Donoho and Stark. We also discuss various properties of the sets of fixed measure maximizing the quadratic spectral concentration of their characteristic functions. As a corollary, we obtain a sharp (up to a constant) estimate for the L2-norms of non-harmonic trigonometric polynomials with alternating coefficients 1 and -1. This talk is part of the Isaac Newton Institute Seminar Series series. ## This talk is included in these lists:- All CMS events
- Featured lists
- INI info aggregator
- Isaac Newton Institute Seminar Series
- School of Physical Sciences
- Seminar Room 1, Newton Institute
- bld31
Note that ex-directory lists are not shown. |
## Other listsLanguage Sciences for Graduate Students Faculty of History events Experimental Psychology## Other talksRobin Wordsworth on "‘Life beyond planetary gravity wells" Lightning Session Gauge origami and Oh-Thomas virtual cycles Spherical Sommerfeld Integrals Things Epidemiologists Should Know - What I've learned about communicating epidemiology and statistics to the public Metric approximation of set-valued functions by integral operators |