49 results on '"Shadrin, Sergey"'
Search Results
2. Generalized Cohomological Field Theories in the Higher Order Formalism
- Author
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Dotsenko, Vladimir, Shadrin, Sergey, and Tamaroff, Pedro
- Published
- 2023
- Full Text
- View/download PDF
3. Maurer-Cartan Methods in Deformation Theory: The Twisting Procedure
- Author
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Dotsenko, Vladimir, Shadrin, Sergey, and Vallette, Bruno
- Published
- 2023
- Full Text
- View/download PDF
4. Elements of spin Hurwitz theory: closed algebraic formulas, blobbed topological recursion, and a proof of the Giacchetto–Kramer–Lewański conjecture
- Author
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Alexandrov, Alexander and Shadrin, Sergey
- Published
- 2023
- Full Text
- View/download PDF
5. Bi-Hamiltonian Recursion, Liu–Pandharipande Relations, and Vanishing Terms of the Second Dubrovin–Zhang Bracket
- Author
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Iglesias, Francisco Hernández and Shadrin, Sergey
- Published
- 2022
- Full Text
- View/download PDF
6. Detecting Wheel Slip to Suppress Self-Excited Oscillations in Braking Mode.
- Author
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Klimov, Aleksander V., Ospanbekov, Baurzhan K., Antonyan, Akop V., Anisimov, Viktor R., Dvoeglazov, Egor A., Novogorodov, Danila A., Keller, Andrey V., Shadrin, Sergey S., Makarova, Daria A., Ershov, Vladimir S., and Furletov, Yury M.
- Subjects
ANTILOCK brake systems in automobiles ,REGENERATIVE braking ,BRAKE systems ,DYNAMIC loads ,INTEGRATED software - Abstract
The wheels of decelerating vehicles in braking mode roll with increased slip, up to complete lock-up, which is a negative phenomenon. This is effectively managed by the anti-lock braking system (ABS). However, in the course of braking, especially before the system activation, self-excited oscillatory processes with high amplitudes may occur, causing increased dynamic loads on the drive system. The paper studies the braking processes of a vehicle with an electromechanical individual traction drive in both electrodynamic regenerative and combined braking modes, utilizing the drive and the primary braking system. The theoretical framework is provided for identifying the self-excited oscillation onset conditions and developing a technique to detect wheel slips during braking to suppress these oscillations. To check the functionality of the wheel-slip observer in braking mode, the performance of the self-excited oscillation pulse suppression algorithm was studied in the MATLAB Simulink 2018b software package. The study results can be used to develop control systems equipped with the function of suppressing self-excited oscillations by vehicle motion. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Topological recursion for Kadomtsev–Petviashvili tau functions of hypergeometric type.
- Author
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Bychkov, Boris, Dunin‐Barkowski, Petr, Kazarian, Maxim, and Shadrin, Sergey
- Subjects
PARTITION functions ,QUADRATIC equations ,HYPERGEOMETRIC functions - Abstract
We study the n$n$‐point differentials corresponding to Kadomtsev–Petviashvili (KP) tau functions of hypergeometric type (also known as Orlov–Scherbin partition functions), with an emphasis on their ℏ2$\hbar ^2$‐deformations and expansions. Under the naturally required analytic assumptions, we prove certain higher loop equations that, in particular, contain the standard linear and quadratic loop equations, and thus imply the blobbed topological recursion. We also distinguish two large families of the Orlov–Scherbin partition functions that do satisfy the natural analytic assumptions, and for these families, we prove in addition the so‐called projection property and thus the full statement of the Chekhov–Eynard–Orantin topological recursion. A particular feature of our argument is that it clarifies completely the role of ℏ2$\hbar ^2$‐deformations of the Orlov–Scherbin parameters for the partition functions, whose necessity was known from a variety of earlier obtained results in this direction but never properly understood in the context of topological recursion. As special cases of the results of this paper, one recovers new and uniform proofs of the topological recursion to all previously studied cases of enumerative problems related to weighted double Hurwitz numbers. By virtue of topological recursion and the Grothendieck–Riemann–Roch formula, this, in turn, gives new and uniform proofs of almost all Ekedahl–Lando–Shapiro–Vainshtein (ELSV)‐type formulas discussed in the literature. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. Deformation theory of cohomological field theories.
- Author
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Dotsenko, Vladimir, Shadrin, Sergey, Vaintrob, Arkady, and Vallette, Bruno
- Subjects
- *
GROMOV-Witten invariants , *SYMMETRY groups - Abstract
We develop the deformation theory of cohomological field theories (in short, CohFTs), which is done as a special case of a general deformation theory of morphisms of modular operads. This leads us to introduce two new natural extensions of the notion of a CohFT: homotopy (necessary algebraic toolkit to develop chain-level Gromov–Witten invariants) and quantum (with examples found in the works of Buryak and Rossi on integrable systems). The universal group of symmetries of morphisms of modular operads, based on Kontsevich's graph complex, is shown to be trivial. Using the tautological rings on moduli spaces of curves, we introduce a natural enrichment of Kontsevich's graph complex. This leads to universal groups of non-trivial symmetries of both homotopy and quantum CohFTs, which, in the latter case, is shown to contain both the prounipotent Grothendieck–Teichmüller group and the Givental group. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Towards a bihamiltonian structure for the double ramification hierarchy
- Author
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Buryak, Alexandr, Rossi, Paolo, and Shadrin, Sergey
- Published
- 2021
- Full Text
- View/download PDF
10. Normal forms of dispersive scalar Poisson brackets with two independent variables
- Author
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Carlet, Guido, Casati, Matteo, and Shadrin, Sergey
- Published
- 2018
- Full Text
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11. Poisson cohomology of scalar multidimensional Dubrovin–Novikov brackets
- Author
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Carlet, Guido, Casati, Matteo, and Shadrin, Sergey
- Published
- 2017
- Full Text
- View/download PDF
12. Research into the Peculiarities of the Individual Traction Drive Nonlinear System Oscillatory Processes.
- Author
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Klimov, Alexander V., Ospanbekov, Baurzhan K., Keller, Andrey V., Shadrin, Sergey S., Makarova, Daria A., and Furletov, Yury M.
- Subjects
ELECTRIC drives ,NONLINEAR systems ,POWER transmission ,TRACTION drives ,ENERGY consumption ,OSCILLATIONS - Abstract
Auto-oscillations may occur in moving vehicles in the area where the tire interacts with the support base. The parameters of such oscillations depend on the sliding velocity in the contact patch. As they negatively affect the processes occurring in the electric drive and the mechanical transmission, reducing their energy efficiency, such processes can cause failures in various elements. This paper aims to conduct a theoretical study into the peculiarities of oscillatory processes in the nonlinear system and an experimental study of the auto-oscillation modes of an individual traction drive. It presents the theoretical basis used to analyze the peculiarities of oscillation processes, including their onset and course, the results of simulation mathematical modeling and the experimental studies into the oscillation phenomena in the movement of the vehicle towards the supporting base. The practical value of this study lies in the possibility to use the results in the development of algorithms for the exclusion of auto-oscillation phenomena in the development of vehicle control systems, as well as to use the auto-oscillation processes onset and course analysis methodology to design the electric drive of the driving wheels. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
13. Development of an Electric All-Wheel-Drive Simulation Model Used to Test Torque Distribution Algorithms.
- Author
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Zavatsky, Alexander M., Keller, Andrey V., Shadrin, Sergey S., Makarova, Daria A., and Furletov, Yury M.
- Subjects
DISTRIBUTION (Probability theory) ,ELECTRIC vehicles testing ,CURVILINEAR motion ,SIMULATION methods & models ,ELECTRIC power transmission - Abstract
The paper describes the developed curvilinear motion simulation model for a vehicle with two traction electric motors moving on a solid surface used to study the dynamic properties of a wheeled vehicle and to subject the developed methods to virtual testing. The simulation model of the electric all-wheel drive vehicle is carried out in the Simcenter Amesim environment to account for the dynamic characteristics and features of the vehicle. The simulation model was developed based on the drawn requirements while the assumptions were justified. Inertia characteristics, tire characteristics, suspension elements, grip characteristics, and surface and air resistance were considered, as these factors affect the vehicle longitudinal and transverse dynamics. The article presents the model implemented in the "Labcar" system and confirms its adequacy by comparing it with the data obtained during the full-scale prototype tests. The bench and range tests of a test vehicle with electric transmission equipped with a measuring complex confirmed the adequacy of the developed model. The results of comparative tests allow for the conclusion that the developed model complex is suitable for modeling purposes, including studying, debugging and initial calibrations of the algorithm of torque distribution on the driving axles of all-wheel drive electric vehicle. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
14. Topological recursion, symplectic duality, and generalized fully simple maps
- Author
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Alexandrov, Alexander, Bychkov, Boris, Dunin-Barkowski, Petr, Kazarian, Maxim, and Shadrin, Sergey
- Subjects
High Energy Physics - Theory ,Mathematics - Algebraic Geometry ,High Energy Physics - Theory (hep-th) ,FOS: Mathematics ,FOS: Physical sciences ,Mathematics - Combinatorics ,Mathematical Physics (math-ph) ,Combinatorics (math.CO) ,Algebraic Geometry (math.AG) ,Mathematical Physics - Abstract
For a given spectral curve, we construct a family of symplectic dual spectral curves for which we prove an explicit formula expressing the $n$-point functions produced by the topological recursion on these curves via the $n$-point functions on the original curve. As a corollary, we prove topological recursion for the generalized fully simple maps generating functions., 16 pages
- Published
- 2023
15. Loop equations and a proof of Zvonkine's qr-ELSV formula
- Author
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Dunin-Barkowski, Petr, Kramer, Reinier, Popolitov, Alexandr, and Shadrin, Sergey
- Subjects
Mathematics - Algebraic Geometry ,FOS: Mathematics ,FOS: Physical sciences ,Mathematics - Combinatorics ,Mathematical Physics (math-ph) ,Combinatorics (math.CO) ,14H10, 05A15, 14N10, 14C17 ,Algebraic Geometry (math.AG) ,Mathematical Physics - Abstract
We prove the 2006 Zvonkine conjecture that expresses Hurwitz numbers with completed cycles in terms of intersection numbers with the Chiodo classes via the so-called $r$-ELSV formula, as well as its orbifold generalization, the $qr$-ELSV formula, proposed recently in [KLPS17]., 22 pages. Version 4: improved exposition of the proof
- Published
- 2023
16. Chiodo formulas for the r-th roots and topological recursion
- Author
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Lewanski, Danilo, Popolitov, Alexandr, Shadrin, Sergey, and Zvonkine, Dimitri
- Published
- 2017
- Full Text
- View/download PDF
17. Bihamiltonian Cohomology of KdV Brackets
- Author
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Carlet, Guido, Posthuma, Hessel, and Shadrin, Sergey
- Published
- 2016
- Full Text
- View/download PDF
18. Givental group action on topological field theories and homotopy Batalin–Vilkovisky algebras
- Author
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Dotsenko, Vladimir, Shadrin, Sergey, and Vallette, Bruno
- Published
- 2013
- Full Text
- View/download PDF
19. Givental Graphs and Inversion Symmetry
- Author
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Dunin-Barkowski, Petr, Shadrin, Sergey, and Spitz, Loek
- Published
- 2013
- Full Text
- View/download PDF
20. Topological recursion for Kadomtsev-Petviashvili tau functions of hypergeometric type
- Author
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Bychkov, Boris, Dunin-Barkowski, Petr, Kazarian, Maxim, and Shadrin, Sergey
- Subjects
High Energy Physics - Theory ,Mathematics - Algebraic Geometry ,14H81, 05A15 (Primary) 37K10, 14H30, 14N10, 37K30, 81T45 (Secondary) ,High Energy Physics - Theory (hep-th) ,FOS: Mathematics ,FOS: Physical sciences ,Mathematics - Combinatorics ,Mathematical Physics (math-ph) ,Combinatorics (math.CO) ,Algebraic Geometry (math.AG) ,Mathematical Physics - Abstract
We study the $n$-point differentials corresponding to Kadomtsev-Petviashvili tau functions of hypergeometric type (also known as Orlov-Scherbin partition functions), with an emphasis on their $\hbar^2$-deformations and expansions. Under the naturally required analytic assumptions, we prove certain higher loop equations that, in particular, contain the standard linear and quadratic loop equations, and thus imply the blobbed topological recursion. We also distinguish two large families of the Orlov-Scherbin partition functions that do satisfy the natural analytic assumptions, and for these families we prove in addition the so-called projection property and thus the full statement of the Chekhov-Eynard-Orantin topological recursion. A particular feature of our argument is that it clarifies completely the role of $\hbar^2$-deformations of the Orlov-Scherbin parameters for the partition functions, whose necessity was known from a variety of earlier obtained results in this direction but never properly understood in the context of topological recursion. As special cases of the results of this paper one recovers new and uniform proofs of the topological recursion to all previously studied cases of enumerative problems related to weighted double Hurwitz numbers. By virtue of topological recursion and the Grothendieck-Riemann-Roch formula this, in turn, gives new and uniform proofs of almost all ELSV-type formulas discussed in the literature., 48 pages; several minor corrections and clarifications
- Published
- 2020
21. A Remark on Deformations of Hurwitz Frobenius Manifolds
- Author
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Buryak, Alexandr and Shadrin, Sergey
- Published
- 2010
- Full Text
- View/download PDF
22. Deformation theory of Cohomological Field Theories
- Author
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Dotsenko, Vladimir, Shadrin, Sergey, Vaintrob, Arkady, Vallette, Bruno, Institut de Recherche Mathématique Avancée (IRMA), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), and Université Paris 13 (UP13)
- Subjects
Mathematics - Algebraic Geometry ,18M85, 18G85, 18M70, 53D55, 14H10, 53D45 ,Mathematics::Algebraic Geometry ,Mathematics - Quantum Algebra ,[PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph] ,FOS: Mathematics ,Quantum Algebra (math.QA) ,FOS: Physical sciences ,Mathematical Physics (math-ph) ,Algebraic Geometry (math.AG) ,Mathematical Physics - Abstract
We develop the deformation theory of cohomological field theories (CohFTs), which is done as a special case of a general deformation theory of morphisms of modular operads. This leads us to introduce two new natural extensions of the notion of a CohFT: homotopical (necessary to structure chain-level Gromov--Witten invariants) and quantum (with examples found in the works of Buryak--Rossi on integrable systems). We introduce a new version of Kontsevich's graph complex, enriched with tautological classes on the moduli spaces of stable curves. We use it to study a new universal deformation group which acts naturally on the moduli spaces of quantum homotopy CohFTs, by methods due to Merkulov--Willwacher. This group is shown to contain both the prounipotent Grothendieck--Teichm\"uller group and the Givental group., Comment: submitted version, 57 pages, abstract and introduction rewritten
- Published
- 2020
23. Experimental Autonomous Road Vehicle with Logical Artificial Intelligence
- Author
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Shadrin, Sergey Sergeevich, Varlamov, Oleg Olegovich, and Ivanov, Andrey Mikhailovich
- Subjects
Artificial intelligence -- Usage ,Autonomous vehicles -- Design and construction -- Innovations ,Artificial intelligence ,Transportation industry - Abstract
This article describes some technical issues regarding the adaptation of a production car to a platform for the development and testing of autonomous driving technologies. A universal approach to performing the reverse engineering of electric power steering (EPS) for the purpose of external control is also presented. The primary objective of the related study was to solve the problem associated with the precise prediction of the dynamic trajectory of an autonomous vehicle. This was accomplished by deriving a new equation for determining the lateral tire forces and adjusting some of the vehicle parameters under road test conductions. A Mivar expert system was also integrated into the control system of the experimental autonomous vehicle. The expert system was made more flexible and effective for the present application by the introduction of hybrid artificial intelligence with logical reasoning. The innovation offers a solution to the major problem of liability in the event of an autonomous transport vehicle being involved in a collision., 1. Introduction The desire for the development of more efficient transport services through the use of innovative organizational and technical solutions has fueled the development and implementation of intelligent transport [...]
- Published
- 2017
- Full Text
- View/download PDF
24. A conjectural formula for DRg(a,-a)λg.
- Author
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Buryak, Alexandr, Iglesias, Francisco Hernández, and Shadrin, Sergey
- Subjects
CURVES ,LOGICAL prediction ,MATHEMATICAL formulas ,MATHEMATICAL models ,AUTHORS - Abstract
We propose a conjectural formula for DR
g (a,-a)λg and check all its expected properties. Our formula refines the one point case of a similar conjecture made by the first named author in collaboration with Guéré and Rossi, and we prove that the two conjectures are in fact equivalent, though in a quite non-trivial way. [ABSTRACT FROM AUTHOR]- Published
- 2022
25. Quasi-polynomiality of monotone orbifold Hurwitz numbers and Grothendieck's dessins d'enfants
- Author
-
Kramer, Reinier, Lewanski, Danilo, Shadrin, Sergey, and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
- Subjects
Mathematics - Algebraic Geometry ,General Mathematics ,FOS: Mathematics ,FOS: Physical sciences ,Mathematics - Combinatorics ,Combinatorics (math.CO) ,Mathematical Physics (math-ph) ,Algebraic Geometry (math.AG) ,14N10, 14H57, 05E05 ,Mathematical Physics - Abstract
We prove quasi-polynomiality for monotone and strictly monotone orbifold Hurwitz numbers. The second enumerative problem is also known as enumeration of a special kind of Grothendieck's dessins d'enfants or $r$-hypermaps. These statements answer positively two conjectures proposed by Do-Karev and Do-Manescu. We also apply the same method to the usual orbifold Hurwitz numbers and obtain a new proof of the quasi-polynomiality in this case. In the second part of the paper we show that the property of quasi-polynomiality is equivalent in all these three cases to the property that the $n$-point generating function has a natural representation on the $n$-th cartesian powers of a certain algebraic curve. These representations are the necessary conditions for the Chekhov-Eynard-Orantin topological recursion., 31 pages. Version 2: simplified the computation in section 4.2, also clarifying the deduction of the diagonal part of the A-operators
- Published
- 2019
26. Buryak–Okounkov Formula for the n-Point Function and a New Proof of the Witten Conjecture.
- Author
-
Alexandrov, Alexander, Iglesias, Francisco Hernández, and Shadrin, Sergey
- Subjects
INTERSECTION numbers ,INTERSECTION theory ,MODULI theory ,LOGICAL prediction ,GEOMETRY - Abstract
We identify the formulas of Buryak and Okounkov for the |$n$| -point functions of the intersection numbers of psi-classes on the moduli spaces of curves. This allows us to combine the earlier known results and this one into a principally new proof of the famous Witten conjecture/Kontsevich theorem, where the link between the intersection theory of the moduli spaces and integrable systems is established via the geometry of double ramification cycles. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
27. Towards Lax Formulation of Integrable Hierarchies of Topological Type
- Author
-
van de Leur, Johannes, Carlet, Guido, Shadrin, Sergey, Posthuma, Hessel, Sub Fundamental Mathematics, Sub Algebra,Geometry&Mathem. Logic begr., Fundamental mathematics, Algebra, Geometry & Mathematical Physics (KDV, FNWI), Sub Fundamental Mathematics, Sub Algebra,Geometry&Mathem. Logic begr., and Fundamental mathematics
- Subjects
Hierarchy ,Integrable system ,Infinitesimal ,FOS: Physical sciences ,Statistical and Nonlinear Physics ,Mathematical Physics (math-ph) ,Partition function (mathematics) ,Fundamental lemma ,Topology ,symbols.namesake ,Quadratic equation ,Nonlinear Sciences::Exactly Solvable and Integrable Systems ,symbols ,Hamiltonian (quantum mechanics) ,Korteweg–de Vries equation ,Mathematics::Symplectic Geometry ,Mathematical Physics ,Mathematics - Abstract
To each partition function of cohomological field theory one can associate an Hamiltonian integrable hierarchy of topological type. The Givental group acts on such partition functions and consequently on the associated integrable hierarchies. We consider the Hirota and Lax formulations of the deformation of the hierarchy of N copies of KdV obtained by an infinitesimal action of the Givental group. By first deforming the Hirota quadratic equations and then applying a fundamental lemma to express it in terms of pseudo-differential operators, we show that such deformed hierarchy admits an explicit Lax formulation. We then compare the deformed Hamiltonians obtained from the Lax equations with the analogous formulas obtained in [1, 2], to find that they agree. We finally comment on the possibility of extending the Hirota and Lax formulation on the whole orbit of the Givental group action., Comment: 36 pages
- Published
- 2014
28. Top tautological group of Mg,n
- Author
-
Buryak, Alexandr, Shadrin, Sergey, Zvonkine, Dimitri, Department of Mathematics [ETH Zurich] (D-MATH), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Korteweg-de Vries Institute for Mathematics, University of Amsterdam [Amsterdam] (UvA), Laboratoire de Mathématiques de Versailles (LMV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Algebra, Geometry & Mathematical Physics (KDV, FNWI), KdV Other Research (FNWI), and Faculty of Science
- Subjects
Nonlinear Sciences::Exactly Solvable and Integrable Systems ,Mathematics::Algebraic Geometry ,Physics::Atomic and Molecular Clusters ,[MATH]Mathematics [math] - Abstract
We describe the structure of the top tautological group in the cohomology of the moduli space of smooth genus g curves with n marked points.
- Published
- 2016
29. Toric varieties of Loday's associahedra and noncommutative cohomological field theories.
- Author
-
Dotsenko, Vladimir, Shadrin, Sergey, and Vallette, Bruno
- Subjects
- *
TORIC varieties , *COHOMOLOGY theory , *COMPACT spaces (Topology) , *NONCOMMUTATIVE algebras , *SUBSPACES (Mathematics) - Abstract
We introduce and study several new topological operads that should be regarded as nonsymmetric analogues of the operads of little 2‐discs, framed little 2‐discs, and Deligne–Mumford compactifications of moduli spaces of genus zero curves with marked points. These operads exhibit all the remarkable algebraic and geometric features that their classical analogues possess; in particular, it is possible to define a noncommutative analogue of the notion of cohomological field theory with similar Givental‐type symmetries. This relies on rich geometry of the analogues of the Deligne–Mumford spaces, coming from the fact that they admit several equivalent interpretations: as the toric varieties of Loday's realisations of the associahedra, as the brick manifolds recently defined by Escobar, and as the De Concini–Procesi wonderful models for certain subspace arrangements. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
30. Local topological recursion and Givental theory
- Author
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Shadrin, Sergey
- Published
- 2013
- Full Text
- View/download PDF
31. Combinatorics of Loop Equations for Branched Covers of Sphere.
- Author
-
Dunin-Barkowski, Petr, Orantin, Nicolas, Popolitov, Aleksandr, and Shadrin, Sergey
- Subjects
MAPS ,ALGEBRAIC topology ,QUANTUM measurement - Abstract
We prove, in a purely combinatorial way, the spectral curve topological recursion for the problem of enumeration of bi-colored maps, which are dual objects to dessins d'enfant. Furthermore, we give a proof of the quantum spectral curve equation for this problem. Then we consider the generalized case of four-colored maps and outline the idea of the proof of the corresponding spectral curve topological recursion. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
32. A definition of descendants at one point in graph calculus
- Author
-
Shadrin, Sergey
- Subjects
High Energy Physics::Theory ,Mathematics::Algebraic Geometry ,Mathematics::Geometric Topology - Abstract
We study the genus expansion of Barannikov-Kontsevich solutions of the WDVV equation. In terms of the related graph calculus, we give a definition of descendants at one point and prove that this definition satisfies the topological recursion relations in genera 0, 1, and 2, string and dilaton equations, and the pull-back formula.
- Published
- 2007
33. Quantum spectral curve for the Gromov--Witten theory of the complex projective line.
- Author
-
Dunin-Barkowski, Petr, Mulase, Motohico, Norbury, Paul, Popolitov, Alexander, and Shadrin, Sergey
- Subjects
GROMOV-Witten invariants ,COHOMOLOGY theory ,COMBINATORICS ,REPRESENTATION theory ,SYMPLECTIC geometry ,PROJECTIVE geometry - Abstract
We construct the quantum curve for the Gromov--Witten theory of the complex projective line. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
34. Blobbed topological recursion: properties and applications.
- Author
-
BOROT, GAËTAN and SHADRIN, SERGEY
- Subjects
- *
TOPOLOGICAL algebras , *SET theory , *MATHEMATICAL decomposition , *HOLOMORPHIC functions , *REPRESENTATIONS of graphs , *INTERSECTION graph theory - Abstract
We study the set of solutions (ωg,n)g⩾0,n⩾1 of abstract loop equations. We prove that ωg,n is determined by its purely holomorphic part: this results in a decomposition that we call “blobbed topological recursion”. This is a generalisation of the theory of the topological recursion, in which the initial data (ω0,1, ω0,2) is enriched by non-zero symmetric holomorphic forms in n variables (φg,n)2g−2+n>0. In particular, we establish for any solution of abstract loop equations: (1) a graphical representation of ωg,n in terms of φg,n; (2) a graphical representation of ωg,n in terms of intersection numbers on the moduli space of curves; (3) variational formulas under infinitesimal transformation of φg,n; (4) a definition for the free energies ωg,0 = Fg respecting the variational formulas. We discuss in detail the application to the multi-trace matrix model and enumeration of stuffed maps. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
35. Top tautological group of Mg,n.
- Author
-
Buryak, Alexandr, Shadrin, Sergey, and Zvonkine, Dimitri
- Subjects
- *
COHOMOLOGY theory , *MODULI theory , *CURVES , *MATHEMATICS theorems , *MATHEMATICAL formulas - Abstract
describe the structure of the top tautological group in the cohomology of the moduli space of smooth genus g curves with n marked points. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
36. Top tautological group of Mg,n.
- Author
-
Buryak, Alexandr, Shadrin, Sergey, and Zvonkine, Dimitri
- Subjects
COHOMOLOGY theory ,MODULI theory ,CURVES ,MATHEMATICS theorems ,MATHEMATICAL formulas - Abstract
describe the structure of the top tautological group in the cohomology of the moduli space of smooth genus g curves with n marked points. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
37. The bi-Hamiltonian cohomology of a scalar Poisson pencil.
- Author
-
Carlet, Guido, Posthuma, Hessel, and Shadrin, Sergey
- Subjects
HAMILTONIAN systems ,COHOMOLOGY theory ,POISSON processes ,SPECTRAL sequences (Mathematics) ,KORTEWEG-de Vries equation ,ISOMORPHISM (Mathematics) - Abstract
We compute the bi-Hamiltonian cohomology of an arbitrary dispersionless Poisson pencil in a single dependent variable using a spectral sequence method. As in the Korteweg-de Vries case, we obtain that BH
p d (F,d1 , d2 ) is isomorphic to R for (p,d)=(0,0), to C8 (R) for (p,d)=(1,1), (2,1), (2,3), (3,3), and vanishes otherwise. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
38. De Rham cohomology and homotopy Frobenius manifolds.
- Author
-
Dotsenko, Vladimir, Shadrin, Sergey, and Vallette, Bruno
- Subjects
- *
HOMOTOPY theory , *COHOMOLOGY theory , *FROBENIUS manifolds , *JACOBI method , *POISSON algebras - Abstract
We endow the de Rham cohomology of any Poisson or Jacobi manifold with a natural homotopy Frobenius manifold structure. This result relies on a minimal model theorem for multicomplexes and a new kind of a Hodge degeneration condition. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
39. Quasi-Polynomiality of Monotone Orbifold Hurwitz Numbers and Grothendieck's Dessins d'Enfants
- Author
-
Kramer, Reinier, Lewa\'Nski, Danilo, and Shadrin, Sergey
- Subjects
010102 general mathematics ,0101 mathematics ,01 natural sciences - Abstract
We prove quasi-polynomiality for monotone and strictly monotone orbifold Hurwitz numbers. The second enumerative problem is also known as enumeration of a special kind of Grothendieck's dessins d'enfants or $r$-hypermaps. These statements answer positively two conjectures proposed by Do-Karev and Do-Manescu. We also apply the same method to the usual orbifold Hurwitz numbers and obtain a new proof of the quasi-polynomiality in this case. In the second part of the paper we show that the property of quasi-polynomiality is equivalent in all these three cases to the property that the $n$-point generating function has a natural representation on the $n$-th cartesian powers of a certain algebraic curve. These representations are necessary conditions for the Chekhov-Eynard-Orantin topological recursion., DOCUMENTA MATHEMATICA, Vol 24 (2019), p. 857-898
40. Givental symmetries of Frobenius manifolds and multi-component KP tau-functions
- Author
-
Feigin, Evgeny, van de Leur, Johan, and Shadrin, Sergey
- Subjects
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MATHEMATICAL symmetry , *FROBENIUS manifolds , *PARTITIONS (Mathematics) , *AXIOMS , *RATIONAL numbers , *GROUP theory , *MATHEMATICAL formulas - Abstract
Abstract: We establish a link between two different constructions of the action of the twisted loop group on the space of Frobenius structures. The first construction (due to Givental) describes the action of the twisted loop group on the partition functions of formal (axiomatic) Gromov–Witten theories. The explicit formulas for the corresponding tangent action were computed by Y.-P. Lee. The second construction (due to van de Leur) describes the action of the same group on the space of Frobenius structures via the multi-component KP hierarchies. Our main theorem states that the genus zero restriction of the Y.-P. Lee formulas coincides with the tangent van de Leur action. [Copyright &y& Elsevier]
- Published
- 2010
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41. Integrable systems, Frobenius manifolds and cohomological field theories
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Hernández Iglesias, F., STAR, ABES, Shadrin, Sergey, Carlet, Guido, and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
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Cohomological field theory ,Système intégrable ,Hiérarchie de Dubrovin et Zhang ,[MATH.MATH-AG] Mathematics [math]/Algebraic Geometry [math.AG] ,Espace de modules de courbes stables ,Double ramification cycles ,Théorie cohomologique des champs ,Nonlinear Sciences::Exactly Solvable and Integrable Systems ,Integrable systems ,Moduli space of stable curves ,Dubrovin-Zhang hierarchy ,Frobenius manifolds ,Cycles de ramification double ,Mathematics::Symplectic Geometry ,Variété de Frobenius - Abstract
In this dissertation, we study the underlying geometry of integrable systems, in particular tausymmetric bi-Hamiltonian hierarchies of evolutionary PDEs and differential-difference equations.First, we explore the close connection between the realms of integrable systems and algebraic geometry by giving a new proof of the Witten conjecture, which constructs the string taufunction of the Korteweg-de Vries hierarchy via intersection theory of the moduli spaces of stable curves with marked points. This novel proof is based on the geometry of double ramification cycles, tautological classes whose behavior under pullbacks of the forgetful and gluing maps facilitate the computation of intersection numbers of psi classes.Second, we examine the Dubrovin-Zhang hierarchy, an integrable system constructed from a Frobenius manifold by deforming its associated pencil of Poisson structures of hydrodynamic type. This integrable hierarchy was proved to be Hamiltonian and tau-symmetric, and conjectured to be bi-Hamiltonian. We prove a vanishing theorem for the negative degree terms of the second Poisson bracket, thus providing strong evidence to support this conjecture. The proof of this theorem demonstrates the implications the bi-Hamiltonian recursion relation and tautological relations in the cohomology rings of the moduli spaces of stable curves have on the bi-Hamiltonian structure of the Dubrovin-Zhang hierarchies.Third, we propose a conjectural formula for the simplest non-trivial product of doubleramification cycles DR_g(1,1)lambda_g in terms of cohomology classes represented by standard strata. Although there are known formulas relating double ramification cycles to other, more natural tautological classes, they are much more complicated than the one conjectured here. This conjecture refines the one point case of the Buryak-Guéré-Rossi conjectural tautological relations, which are equivalent to the existence of a Miura transformation relating Buryak's double ramification hierarchies and the Dubrovin-Zhang ones.Finally, we analyze the differential geometry of (2 + 1) integrable systems through infinitedimensional Frobenius manifolds. More concretely, we study, both formally and analytically, the Dubrovin equation of the 2D Toda Frobenius manifold at its irregular singularity. The fact that it is infinite-dimensional implies a qualitatively different behavior than its finite-dimensional analogue, the Frobenius manifold underlying the extended Toda hierarchy. The two most remarkable differences are non-uniqueness of formal solutions to the Dubrovin equation and non-completeness of the analytic ones. These features together greatly complicate the analysis of Stokes phenomenon, which we perform by splitting the space of solutions into infinitely many two-dimensional subspaces., Dans cette thèse, nous étudions la géométrie sous-jacente des systèmes intégrables. Nous nous intéressons particulièrement aux hiérarchies d'EDPs d'évolution, tau-symétriques et bi-Hamiltoniennes.D'abord, nous explorons la relation étroite entre les champs des systèmes intégrables et la géométrie algébrique en donnant une nouvelle démonstration de la conjecture de Witten, qui construit la string tau-fonction de la hiérarchie de Korteweg-de Vries par théorie d'intersection des espaces de modules des courbes stables avec des points marqués. Cette nouvelle démonstration se base sur la géométrie des cycles de ramification double, des classes tautologiques dont le comportement sous des pullbacks des applications forgetful et gluing facilitent le calcul des nombres d'intersection des psi classes.Dans un deuxième temps, nous examinons la hiérarchie de Dubrovin et Zhang, un système intégrable construit en déformant la structure bi-Hamiltonienne de type hydrodynamique associée à une variété de Frobenius. Cette hiérarchie intégrable est Hamiltonienne et tau-symétrique, et est conjecturée bi-Hamiltonienne. Nous démontrons un théorème d'annulation des termes de degrés négatifs du deuxième crochet de Poisson qui fournit des preuves fortes pour soutenir cette conjecture. La démonstration de ce théorème illustre les implications que la récursivité bi-Hamiltonienne et les relations tautologiques en cohomologie des espaces de modules des courbes stables ont sur la structure bi-Hamiltonienne des hiérarchies de Dubrovin et Zhang.Dans un troisième temps, nous conjecturons une formule pour le plus simple des produits non triviaux des cycles de ramification double DR_g(1,1)lambda_g en termes des classes de cohomologie réprésentées par les strates standards. Malgré l'existence de formules qui mettent en relation des cycles de ramification double avec autres classes tautologiques plus naturelles, elles sont beaucoup plus compliquées que celle proposée ici. Cette conjecture précise dans le cas d'un point les relations tautologiques conjecturales de Buryak, Guéré et Rossi, qui sont équivalentes à l'existence d'une transformation de Miura qui relie la hiérarchie de ramification double de Buryak et celle de Dubrovin et Zhang.Finalement, nous analysons la géométrie différentielle des systèmes intégrables en (2 + 1) dimensions par variétés de Frobenius de dimension infinie. Plus concrètement, nous étudions, formèlement et analytiquement, l'équation de Dubrovin de la variété de Frobenius de la hiérarchie de Toda bidimensionnelle à sa singularité irrégulière. Le fait qu'elle est de dimension infinie implique un comportement qualitativement différent de celui de son analogue en dimension finie, la variété de Frobenius sous-jacente à la hiérarchie de Toda élargie. Les deux différences les plus rémarcables sont que les solutions formèles de l'équation de Dubrovin ne sont pas uniques et que les solutions analytiques ne forment pas un système complet. Conjointement ces deux caractéristiques compliquent l'analyse du phénomène de Stokes, que nous réalisons en divisant l'espace des solutions en une infinité des sous-espaces de dimension deux.
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- 2022
42. Cycles of curves, cover counts, and central invariants
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Kramer, R., Shadrin, Sergey, Carlet, Guido, and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
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Mathematics::Algebraic Geometry - Abstract
The first topic of this dissertation is the moduli space of curves. I define half-spin relations, specialising Pandharipande-Pixton-Zvonkine’s spin relations, to reprove Buryak-Shadrin-Zvonkine’s result on the dimension of the top Chow group for the open moduli space, and give new bounds for the lower groups. I also use these relations to reduce Faber’s intersection number conjecture to a combinatorial identity. The second is Hurwitz numbers. I prove quasi-polynomiality for orbifold simple, weakly and strictly monotone, and spin Hurwitz numbers. In the first case, this was already known, via the Johnson-Pandharipande-Tseng formula, and in the other cases this is new. I also prove that triply mixed double Hurwitz numbers satisfy piecewise polynomiality. For monotone and for orbifold spin Hurwitz numbers, I derive a cut-and-join-equation and prove topological recursion (for r = 2 and for genus zero, general r in the latter case). The former was known by Goulden-Guay-Paquet-Novak. The latter proves Zvonkine’s r-ELSV formula for these cases. The third is integrable hierarchies. I reprove a result by Alexandrov, showing that triple Hodge integrals on the moduli space of curves satisfy the Kadomtsev-Petviashvili hierarchy, generalising Kazarian’s single Hodge integral proof. I give a new and purely cohomological proof of Dubrovin-Liu-Zhang’s theorem, that integrable hierarchies described by dispersive semi-simple Poisson pencils are classified by central invariants, and I streamline Carlet-Posthuma-Shadrin’s proof that this is an equivalence.
- Published
- 2019
43. Proper Lie groupoids and their orbit spaces
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Wang, K.J.L., Posthuma, Hessel Bouke, Shadrin, Sergey, and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
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Mathematics::Operator Algebras ,Mathematics::K-Theory and Homology ,Mathematics::Category Theory ,Mathematics::Symplectic Geometry - Abstract
This thesis studies proper Lie groupoids on three levels: the groupoids themselves, their induced foliations, and their orbit spaces. Proper Lie groupoids are shown to admit desingularisations via a successive blow-up procedure, whereby orbits are systematically added to achieve regularity. Regarding their foliations, a thorough treatment of the known integration results for singular foliations is included. Moreover, the underlying orbit spaces of proper Lie groupoids are studied. This is done by first providing an intrinsic definition of a so-called orbispace using atlases, both in the language of Morita bibundles, and in the language of Morita equivalences through fractions. An orbispace is said to be proper if it admits a proper defining atlas. It is then shown that proper Lie groupoids, up to a precise notion of Morita equivalence, correspond exactly to such proper orbispaces. This can be interpreted as the statement that proper orbispaces form a subcategory of all differentiable stacks. All of these developments mirror the well-known correspondences between regular proper Lie groupoids, regular foliations, and orbifolds. The above results are further shown to hold in the setting of proper Riemannian groupoids. In particular the desingularisation procedure can be performed in such a way that the regularised groupoid has arbitrarily small Gromov—Hausdorff distance from the original groupoid. Moreover, proper Riemannian orbispaces are defined and shown to correspond precisely to appropriate equivalence classes of proper Riemannian groupoids. This thesis contains various other results, including those on holonomy groupoids of orbit-like foliations, and a de Rham theorem for orbispaces.
- Published
- 2018
44. Cohomological field theories and global spectral curves
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Popolitov, A., Shadrin, Sergey, Posthuma, Hessel Bouke, and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
- Abstract
In my thesis I consider interplay between several different structures in mathematical physics. These structures are used to solve a large class of problems in enumerative algebraic geometry and combinatorics in a universal way. The problems can range from counting certain one-dimensional drawings on two-dimensional surfaces to counting maps of certain type from a two-dimensional surface to some higher-dimensional space. The structures that we study in this thesis allow to encode the solutions to this type of enumerative and combinatorial problems in some general compact form. In one approach the solutions to the enumerative problems are encoded in a complex algebraic curve with certain functions on it. From this initial small set of data one can reconstruct the full solution with the help of a recursive procedure that is absolutely universal and does not depend on a particular problem. In another approach the solutions to the enumerative problems are encoded as certain integrals over some complicated spaces that parametrize different complex structures on two-dimensional surfaces. This reveals that the solutions to the enumerative problems reflect the geometric properties of the space of complex structures, also in a universal way. These two approaches turn out to be related in many different ways. In this thesis their relation is studied in the framework of an advanced differential geometric structure called Frobenius manifold.
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- 2017
45. Moduli spaces of curves and enumerative geometry via topological recursion
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Lewański, D., Shadrin, Sergey, and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
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Mathematics::Algebraic Geometry ,Mathematics::Symplectic Geometry - Abstract
The thesis considers several enumerative geometric problems concerning the topology of the moduli space of curves and their combinatorics. These enumerative geometric problems are analysed from different intertwined points of view and using different mathematical tools, including Hurwitz theory, Givental theory, cohomological field theories, integrable hierarchies, Fock spaces, quantum curves, and a relatively new powerful technique introduced by Chekhov, Eynard and Orantin known as topological recursion. These subjects lie in the interplay between enumerative algebraic geometry, differential geometry and mathematical physics.
- Published
- 2017
46. Gromov-Witten theory and spectral curve topological recursion
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Dunin-Barkovskiy, P., Shadrin, Sergey, and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
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Mathematics::Symplectic Geometry - Abstract
Gromov-Witten theory and spectral curve topological recursion are important parts of modern algebraic geometry and mathematical physics. In my thesis I study relations between these theories and some important new aspects and applications of them. In particular, a construction for a local spectral curve which produces the same invariants as a given Gromov-Witten theory is presented in the thesis, as well as constructions for quantum spectral curves for several important theories, and a new proof of the so-called ELSV formula.
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- 2015
47. Hidden structures of knot invariants
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Sleptsov, A., Shadrin, Sergey, Morozov, A.Y., and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
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Mathematics::Quantum Algebra ,Mathematics::Geometric Topology - Abstract
In the present thesis we consider polynomial knot invariants and their properties. We discuss a connection of HOMFLY polynomials with Hurwitz covers and represent a generating function for the HOMFLY polynomial of a given knot in all representations as Hurwitz partition function, i.e. the dependence of the HOMFLY polynomials on representation R is naturally captured by symmetric group characters (cut-and-join eigenvalues). The genus expansion and the loop expansion through Vassiliev invariants explicitly demonstrate this phenomenon. We study the genus expansion (also known as the large N expansion) and discuss its properties. Then we also consider the loop expansion in details. In particular, we give an algorithm to calculate Vassiliev invariants, give some examples and discuss relations among Vassiliev invariants. Next we consider superpolynomials for torus knots defined via double affine Hecke algebra. We claim that the superpolynomials are not functions of Hurwitz type: symmetric group characters do not provide an adequate linear basis for their expansions. Deformation to superpolynomials is, however, straightforward in the multiplicative basis: the Casimir operators are beta-deformed to Hamiltonians of the Calogero-Moser-Sutherland system. Applying this trick to the genus and Vassiliev expansions, we observe that the deformation is fully straightforward only for the thin knots. Beyond the family of thin knots additional algebraically independent terms appear in the Vassiliev expansions. This can suggest that the superpolynomials do in fact contain more information about knots than the colored HOMFLY and Kauffman polynomials.
- Published
- 2014
48. Hurwitz numbers, moduli of curves, topological recursion, Givental's theory and their relations
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Spitz, L., Shadrin, Sergey, and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
- Abstract
The study of curves is an important area of research in algebraic geometry and mathematical physics. In my thesis I study so-called moduli spaces of curves; these are spaces that parametrize all curves with some specified properties. In particular, I study maps from curves to other spaces, recursive relations between numbers of curves with specified properties and equations for generating functions of these numbers. Krommen vormen een belangrijk onderzoeksgebied binnen de algebraïsche meetkunde. In mijn proefschrift bestudeer ik zogenaamde moduliruimten van krommen; dit zijn ruimten die alle krommen met gegeven eigenschappen parametriseren. Verschillende aspecten die ik onderzoek zijn afbeeldingen van krommen naar andere ruimten, recursieve relaties tussen aantallen krommen met gegeven eigenschappen en vergelijkingen voor genererende functies van dit soort aantallen.
- Published
- 2014
49. Topology of the moduli space of curves and integrable hierarchies
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Buryak, A., Shadrin, Sergey, and Algebra, Geometry & Mathematical Physics (KDV, FNWI)
- Published
- 2013
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