Proceedings of the Seminar on Functional Analysis . Issue 6", edited by well-known scientists, in particular M. A. Krasnoselsky is a unique publication that will be a real find for anyone interested in modern trends in mathematics and functional analysis. This collection includes the results of the seminar, which gathers under one roof leading specialists and researchers dealing with topical problems of functional analysis. Functional analysis is the field of mathematics that studies the properties of functionals and function spaces. The sixth issue contains works that cover both theoretical aspects and practical applications of functional analysis. Readers will be able to immerse themselves in the discussion of topics such as operator spaces, spectral theory, methods for solving differential equations, and much more. Each article in the collection is written with a high level of scientific rigor, which makes them valuable for both students and experienced researchers. This book will be especially interesting for those who study mathematics at the master's and postgraduate level, as well as teachers and practicing scientists. If you are passionate about mathematical analysis, function theory, or are looking for new approaches to solving complex problems, then "Works of the workshop on functional analysis. Issue 6 "will be for you not only a useful source of knowledge, but also an inspiration for further research. The topics raised in this issue cover a wide range of topics, from abstract mathematical concepts to practical applications in physics and engineering. The book highlights the importance of functional analysis in contemporary scientific research and its impact on other areas such as statistics, probability theory, and even economics. This makes it relevant not only for mathematicians, but also for specialists from related disciplines who are looking for new tools for analysis and modeling. The style of the author and editors is clear and accessible, which allows readers who do not even have deep knowledge in the field of functional analysis to understand the main ideas and concepts. M. A. Krasnoselsky, as one of the leading specialists in this field, is known for his works, which often become fundamental in mathematical literature. His other well-known works, such as "Linear Operators in Functional Space" and "