CMRNP

Seminar "Bogoljub Stanković" (since 1962)

Chair: Academician Stevan Pilipović

Monday, 12.15, DMI room 60

07.12.2020.	Nenad Teofanov Continuity properties of some classes of Wick and anti-Wick operators. Sažetak We give a sample of recent results of joint work with J. Toft and P. Wahlberg. In the first part of the talk, we provide historical background and motivation for our research by considering Hermite functions, linear harmonic oscillator, and different spaces of(ultra)differentiable functions, notably Pilipovic spaces. Thereafter, we discuss the Bargmann transform and analytic pseudodifferential operators. In particular, we consider Wick and anti-Wick connection. We notice that our findings can be used to recover and improve some known results in the context of real analysis.
20.01.2020.	Stevan Pilipović Dijagonalizacija pseudo-diferencijalnih operatora
20.01.2020.	Federico Bastianoni, University of Turin, Italia Decay and smoothness for eigenfunctions of localization operators Sažetak In this talk we present localization operators A_a ^φ1,φ2 in the framework of time-frequency analysis. After an historical introduction, we represent A_a ^φ1,φ2 as a Weyl operator and show modulation spaces which appear to be the appropriate class for symbols a. Some results about decay and smoothness for L2 -eigenfunctions of localization operators from [1], an article by E. Cordero, F. Nicola and myself, are shown. Eventually, we exhibit an expected generalization in the setting of Gelfand-Shilov spaces. This will consist of a research topic in collab- oration with N. Teofanov. Reference [1] F. Bastianoni, E. Cordero and F. Nicola. Decay and Smoothness for Eigenfunctions of Localization Operators. Submitted. ArXiv:1902.03413v2
13.01.2020.	Tijana Šukilović, Matematički fakultet, Beograd Geodezijski ekvivalentne metrike na homogenim prostorima Sažetak Dve metrike na mnogostrukosti su projektivno ili geodezijski ekvivalentne ako se skupovi njihovih neparametrizovanih geodezijskih krivih poklapaju. Na ovom predavanju biće razmatrane G-invarijantne metrike proizvoljne signature na homogenom prostoru G/H. Biće pokazano da geodezijski ekvivalentne G-invarijantne metrike na G/H moraju imati istu Levi-Čivita povezanost, odnosno moraju biti afino ekvivalentne. Takođe, posebna pažnja će biti posvećena vezi između geodezijske ekvivalentnosti i grupa holonomija. Specijalno, za slučaj Lijevih grupa, biće prikazan algoritam kojim se za datu levo-invarijantnu metriku konstruišu sve njoj geodezijski ekvivalentne metrike.
23. 12. 2019.	Filip Tomić, University of Novi Sad Skoro analitička proširenja i talasni front Sažetak U radu [1] je dokazan rezultat o reprezentaciji ultradistribucija kao graničnih vrednosti analitičkih funkcija. U dokazu se koriste skoro analitička proširenja ultradiferencijabilnih funkcija kao njihovih test prostora. Takva proširenja su nedavno analizirana i u radu [4]. Jedna od primena ovakvih rezultata je u analizi talasnog fronta kompozicije ultradistribu- cija sa analitičkim funkcijama (pullback, videti [2]). U okviru predavanja će biti dat prikaz postojećih rezultata vezanih za granične vrednosti analitičkih funkcija u prostorima ultradistribucija. Takodje će biti prikazani i rezultati u okviru uopštenih funkcija Ževrea. Reference [1] Pilipović, Stevan Structural theorems for ultradistributions Different aspects of differentiability (Warsaw, 1993). Dissertationes Math. (Rozprawy Mat.) 340 (1995), 223–235. [2] Pilipović, Stevan Microlocal properties of ultradistributions. Composition and kernel type operators. 50th anniversary of the Mathematical Institute, Serbian Academy of Sciences and Arts (Belgrade, 1996). Publ. Inst. Math. (Beograd) (N.S.) 64(78) (1998), 85–97. [3] R. Carmichael, A. Kaminski, S. Pilipović, Notes on Boundary Values in Ultradistribution Spaces, Lecture Notes Series of Seul University, 49, 1999. [4] Fürdös, Stefan; Nenning, David Nicolas; Rainer, Armin; Schindl, Gerhard Almost analytic extensions of ultradifferentiable functions with applications to microlocal analysis. J. Math. Anal. Appl. 481 (2020), no. 1, 123451, 51 pp. [5] H. Komatsu, Ultradistributions, I: Structure theorems and a characterization. J. Fac. Sci. Univ. Tokyo, Sect. IA Math., 20 1 (1973), 25–105. [6] Lars Hörmander, The Analysis of Linear Partial Differential Operators I, Springer, 1990. [7] Pilipović, Stevan, Teofanov, Nenad, Tomić, Filip, Boundary values in extended Gevrey ultradistributions, in preperation.
12.12. 2019. (četvrtak)	Vesa Vuojamo, Aalto University, Finland Euclidean time-frequency Transforms Sažetak We will present some new Euclidean space results on characterizing properties of the Cohen class time-frequency transformsand the corresponding pseudo-differential quantization.
09. 12. 2019.	Miloš Kurilić, University of Novi Sad, Serbia Koliko modela ima teorija? Sažetak Sa I(T) označavamo (kardinalni) broj neizomorfnih prebrojivih modela prebrojive kompletne teorije prvog reda T. Ovaj broj je manji ili jednak kontinuumu (c), a klasični primeri Cantora, Ehrenfeuchta i Vaughta pokazuju da I(T) može da bude bilo koji prirodan broj sem 2, te da postoje teorije sa prebrojivo mnogo kao i teorije sa kontinuum mnogo modela. 1959. godine (objavljeno 1961.) Robert Vaught je postavio pitanje koje se svodi na pretpostavku da, ako je I(T) neprebrojiv kardinalni broj, onda je I(T) = c (Vaught’s conjecture). Kao što je Cantorov problem kontinuuma(CH, razrešen u radovima Godela (1943) i Cohena (1963)) bio prvi na Hilbertovoj listi otvorenih problema za 20. vek (1900), Vaughtova hipoteza,tj. “problem kontinuuma za modele” je prvi na listi otvorenih problema teorije modela (Wikipedia). Do sada, Vaughtova hipoteza je potvrđena za neke klase struktura (tj. njihovih teorija). Npr. za linearna uređenja (Rubin, 1974), drveta (Steel, 1978), omega-stabilne teorije (Shelah, Harrington, Makkai, 1984), o-minimalne teorije (Mayer, 1988). Na predavanju će biti dato više detalja i primera koji se tiču ovog problema; biće prikazani i neki novi rezultati
02. 12. 2019.	Nikola Sarajlija, University of Novi Sad, Serbia Primena min-max principa u PDJ
04. 11. 2019.	Nenad Teofanov, University of Novi Sad, Serbia Multipliers: From the Fourier multipliers to continuous frames
21. 10. 2019.	Scientific organization and project activities
14. 10. 2019.	Jelena Aleksić, Univeristy of Novi Sad, Serbia Two scale defect measures
07. 10. 2019.	Lenny Neyt, Ghent University, Belgium Contributions to the generalised asymptotics of ultradistributions
09. 04. 2019.	Danka Lučić, University of Jyväskylä, Finland Weakly differentiable functions on metric measure spaces and the notion of infinitezimal Hilbertianity
09. 04. 2019.	Enrico Pasqualetto, University of Jyväskylä, Finland Universal infinitesimal Hilberianity of sub-Riemannian manifolds
18. 03. 2019.	Vladimir Kapustin, V. A. Stelkov Mathematical Institute, St.Petesburg, Russia Beurling's theorem, Davenport's formula, and the Riemann Hypothesis
17. 12. 2018.	Endre Süli, Oxford University, Great Britain Analysis and approximation of Hamilton–Jacobi–Bellman equations with Cordes coefficients
10. 12. 2018.	Nenad Morača Varijacije reverzibilnosti
03. 12. 2018.	Dogovor o rasporedu predavanja
26. 11. 2018.	Nevena Mićić Otkazano
19. 11. 2018.	Božidar Jovanović, MI SANU, Beograd Uopštenje Jakobi-Mamfordovih sistema i afini primovi verijeteti

Seminar for Numerical Mathematics

Chair: Prof. Dr Nataša Krejić

Friday, 13.15, DMI PhD room -- the first floor in the new part

17. 12. 2020.	Nataša Krejić Adversarial Carlini Wagner Attack and Counter Attack
03. 12. 2020.	Daniela di Serafino LSOS: a line-search second-order algorithmic framework for stochastic optimization problems
26. 11. 2020.	Greta Malaspina A modified Levenberg-Marquardt method for large scale network adjustment
19. 11. 2020.	Marco Viola Using gradient directions to get global convergence of Newton-type methods
12. 11. 2020.	Nataša Krklec Jerinkić EFIX: Exact Fixed Point Methods for Distributed Optimization
03. 11. 2020.	Tijana Ostojić BFGS methods for minimizing nonsmooth convex functions with variable accuracy
27. 05. 2019.	Ljiljana Teofanov SDFEM on a Duran-type mesh for a convection-diffusion problem
20. 05. 2019.	Tijana Stojančević On an inexact restoration subgradient method
13. 05. 2019.	Goran Radojev A posteriori error estimations for parabolic problems
06. 05. 2019.	Nataša Krklec Jerinkić Distributed methods for system of linear equations
22. 04. 2019.	Davor Kumozec Numerical solution to transport equation by method of characteristics
25. 03. 2019.	Zoltan Pap Projection based CG methods for solving systems of large-scale nonlinear monotone equations
18. 03. 2019.	Zoranka Desnica Robust optimization
11. 01. 2019.	Dušan Jakovetić TBA
21. 12. 2018.	Bojana Anđelković Ćirković Optimization Techniques Applied on Problem of Explaining Individual Classifications
14. 12. 2018.	Tijana Stojančević Subgradient Optimization Methods
07. 12. 2018.	Katarina Vla Panić Reduction Method with Biased Gradient Approximation
23. 11. 2018.	Greta Malaspina Methods for Finite Sum Optimization
21. 11. 2018.	Stephan Schluter Time Series Outliers Detection via Wavelets
16. 11. 2018.	Nataša Krejić Inexact Restoration - Trust Region Approach
09. 11. 2018.	Stevan Armacki Distributed Trust Region Methods

Department of Mathematics and Informatics
Faculty of Sciences, University of Novi Sad
Trg Dositeja Obradovića 4, 21000 Novi Sad, Serbia
phone: +381 (0)21 6350449, +381 (0)21 4852850, +381 (0)21 4852870; fax: +381 (0)21 6350458