16 results on '"Junwu Tu"'
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2. A progression analysis of motor features in Parkinson's disease based on the mapper algorithm
- Author
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Ling-Yan Ma, Tao Feng, Chengzhang He, Mujing Li, Kang Ren, and Junwu Tu
- Subjects
progression analysis ,Parkinson's disease ,mapper algorithm ,Markov chain ,prediction model ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
BackgroundParkinson's disease (PD) is a neurodegenerative disease with a broad spectrum of motor and non-motor symptoms. The great heterogeneity of clinical symptoms, biomarkers, and neuroimaging and lack of reliable progression markers present a significant challenge in predicting disease progression and prognoses.MethodsWe propose a new approach to disease progression analysis based on the mapper algorithm, a tool from topological data analysis. In this paper, we apply this method to the data from the Parkinson's Progression Markers Initiative (PPMI). We then construct a Markov chain on the mapper output graphs.ResultsThe resulting progression model yields a quantitative comparison of patients' disease progression under different usage of medications. We also obtain an algorithm to predict patients' UPDRS III scores.ConclusionsBy using mapper algorithm and routinely gathered clinical assessments, we developed a new dynamic models to predict the following year's motor progression in the early stage of PD. The use of this model can predict motor evaluations at the individual level, assisting clinicians to adjust intervention strategy for each patient and identifying at-risk patients for future disease-modifying therapy clinical trials.
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- 2023
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3. On the Morita invariance of Categorical Enumerative Invariants
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Lino Amorim and Junwu Tu
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Mathematics - Algebraic Geometry ,Mathematics - Symplectic Geometry ,Mathematics - K-Theory and Homology ,FOS: Mathematics ,Symplectic Geometry (math.SG) ,K-Theory and Homology (math.KT) ,Algebraic Geometry (math.AG) - Abstract
Categorical Enumerative Invariants (CEI) are invariants associated with unital cyclic $A_\infty$-categories that are smooth, proper and satisfy the Hodge-to-de-Rham degeneration property. In this paper, we formulate and prove their Morita invariance. In particular, when applied to derived categories of coherent sheaves, this yields new birational invariants of smooth and proper Calabi-Yau $3$-folds., Comments welcome!
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- 2022
4. Computing a categorical Gromov–Witten invariant
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Andrei Caldararu and Junwu Tu
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Pure mathematics ,Algebra and Number Theory ,Computation ,010102 general mathematics ,01 natural sciences ,Elliptic curve ,0103 physical sciences ,Gromov–Witten invariant ,010307 mathematical physics ,0101 mathematics ,Invariant (mathematics) ,Mirror symmetry ,Categorical variable ,Mathematics ,Symplectic geometry - Abstract
We compute the $g=1$, $n=1$ B-model Gromov–Witten invariant of an elliptic curve $E$ directly from the derived category $\mathsf{D}_{\mathsf{coh}}^{b}(E)$. More precisely, we carry out the computation of the categorical Gromov–Witten invariant defined by Costello using as target a cyclic $\mathscr{A}_{\infty }$ model of $\mathsf{D}_{\mathsf{coh}}^{b}(E)$ described by Polishchuk. This is the first non-trivial computation of a positive-genus categorical Gromov–Witten invariant, and the result agrees with the prediction of mirror symmetry: it matches the classical (non-categorical) Gromov–Witten invariants of a symplectic 2-torus computed by Dijkgraaf.
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- 2020
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5. Categorical primitive forms of Calabi–Yau $$A_\infty $$-categories with semi-simple cohomology
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Lino Amorim and Junwu Tu
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Mathematics - Algebraic Geometry ,Mathematics::K-Theory and Homology ,Mathematics - Symplectic Geometry ,Mathematics::Category Theory ,General Mathematics ,Mathematics - K-Theory and Homology ,FOS: Mathematics ,Symplectic Geometry (math.SG) ,General Physics and Astronomy ,K-Theory and Homology (math.KT) ,Algebraic Geometry (math.AG) ,Mathematics::Algebraic Topology ,Mathematics::Symplectic Geometry - Abstract
We study categorical primitive forms for Calabi--Yau $A_\infty$ categories with semi-simple Hochschild cohomology. We classify these primitive forms in terms of certain grading operators on the Hochschild homology. We use this result to prove that, if the Fukaya category ${{\sf Fuk}}(M)$ of a symplectic manifold $M$ has semi-simple Hochschild cohomology, then its genus zero Gromov--Witten invariants may be recovered from the $A_\infty$-category ${{\sf Fuk}}(M)$ together with the closed-open map. An immediate corollary of this is that in the semi-simple case, homological mirror symmetry implies enumerative mirror symmetry., Comment: Comments welcome. v2: sign corrections and other improvements. v3: some improvements
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- 2022
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6. Categorical Primitive Forms and Gromov–Witten Invariants of An Singularities
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Andrei Caldararu, Si Li, and Junwu Tu
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Pure mathematics ,General Mathematics ,010102 general mathematics ,Gravitational singularity ,02 engineering and technology ,0101 mathematics ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,Categorical variable ,Mathematics - Abstract
We introduce a categorical analogue of Saito’s notion of primitive forms. For the category $\textsf{MF}(\frac{1}{n+1}x^{n+1})$ of matrix factorizations of $\frac{1}{n+1}x^{n+1}$, we prove that there exists a unique, up to non-zero constant, categorical primitive form. The corresponding genus zero categorical Gromov–Witten invariants of $\textsf{MF}(\frac{1}{n+1}x^{n+1})$ are shown to match with the invariants defined through unfolding of singularities of $\frac{1}{n+1}x^{n+1}$.
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- 2019
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7. The inverse function theorem for curved L-infinity spaces.
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Amorim, Lino and Junwu Tu
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DIFFERENTIAL geometry ,SMOOTHNESS of functions ,HOMOMORPHISMS ,INVERSE functions ,ALGEBRA - Abstract
In this paper, we prove an inverse function theorem in derived differential geometry. More concretely, we show that a morphism of curved L1 spaces which is a quasi-isomorphism at a point has a local homotopy inverse. This theorem simultaneously generalizes the inverse function theorem for smooth manifolds and the Whitehead theorem for L1 algebras. The main ingredients are the obstruction theory for L1 homomorphisms (in the curved setting) and the homotopy transfer theorem for curved L1 algebras. Both techniques work in the A1 case as well. [ABSTRACT FROM AUTHOR]
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- 2022
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8. The inverse function theorem for curved L-infinity spaces
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Lino Amorim and Junwu Tu
- Subjects
Mathematics - Differential Geometry ,Mathematics - Algebraic Geometry ,Algebra and Number Theory ,Differential Geometry (math.DG) ,Mathematics - K-Theory and Homology ,Mathematics - Quantum Algebra ,FOS: Mathematics ,Quantum Algebra (math.QA) ,K-Theory and Homology (math.KT) ,Geometry and Topology ,Mathematics::Algebraic Topology ,Algebraic Geometry (math.AG) ,Mathematical Physics - Abstract
In this paper we prove an inverse function theorem in derived differential geometry. More concretely, we show that a morphism of curved $L_\infty$ spaces which is a quasi-isomorphism at a point has a local homotopy inverse. This theorem simultaneously generalizes the inverse function theorem for smooth manifolds and the Whitehead theorem for $L_\infty$ algebras. The main ingredients are the obstruction theory for $L_\infty$ homomorphisms (in the curved setting) and the homotopy transfer theorem for curved $L_\infty$ algebras. Both techniques work in the $A_\infty$ case as well., Comment: Comments welcome! Title change in the second version. v4: references updated
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- 2020
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9. Tensor product of cyclic 𝐴_{∞}-algebras and their Kontsevich classes
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Lino Amorim and Junwu Tu
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Pure mathematics ,Tensor product ,Applied Mathematics ,General Mathematics ,010102 general mathematics ,0103 physical sciences ,MathematicsofComputing_GENERAL ,010307 mathematical physics ,0101 mathematics ,01 natural sciences ,Mathematics - Abstract
Given two cyclic A ∞ A_\infty -algebras A A and B B , in this paper we prove that there exists a cyclic A ∞ A_\infty -algebra structure on their tensor product A ⊗ B A\otimes B which is unique up to a cyclic A ∞ A_\infty -quasi-isomorphism. Furthermore, the Kontsevich class of A ⊗ B A\otimes B is equal to the cup product of the Kontsevich classes of A A and B B on the moduli space of curves.
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- 2018
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10. Categorical Saito theory, I: A comparison result
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Junwu Tu
- Subjects
Comparison theorem ,Pure mathematics ,General Mathematics ,Quantization (signal processing) ,010102 general mathematics ,Formality ,01 natural sciences ,Matrix (mathematics) ,Mathematics - Algebraic Geometry ,Singularity ,Hypersurface ,Mathematics - Symplectic Geometry ,Mathematics::K-Theory and Homology ,0103 physical sciences ,Mathematics - Quantum Algebra ,FOS: Mathematics ,Quantum Algebra (math.QA) ,Symplectic Geometry (math.SG) ,010307 mathematical physics ,0101 mathematics ,Categorical variable ,Algebraic Geometry (math.AG) ,Hodge structure ,Mathematics - Abstract
In this paper, we present an explicit cyclic minimal $A_\infty$ model for the category of matrix factorizations $\MF(W)$ of an isolated hypersurface singularity. The key observation is to use Kontsevich's deformation quantization technique. Pushing this idea further, we use the Tsygan formality map to obtain a comparison theorem that the categorical Variation of Semi-infinite Hodge Structure of $\MF(W)$ is isomorphic to Saito's original geometric construction in primitive form theory. An immediate corollary of this comparison result is that the analogue of Caldararu's conjecture holds for the category $\MF(W)$., Comment: 31 pages
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- 2019
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11. Categorical Saito theory, II: Landau-Ginzburg orbifolds
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Junwu Tu
- Subjects
General Mathematics ,010102 general mathematics ,Zero (complex analysis) ,14B07, 18G55 ,Isolated singularity ,Symmetry group ,01 natural sciences ,Quintic function ,law.invention ,Combinatorics ,Mathematics - Algebraic Geometry ,Matrix (mathematics) ,Invertible matrix ,law ,0103 physical sciences ,FOS: Mathematics ,010307 mathematical physics ,0101 mathematics ,Mirror symmetry ,Algebraic Geometry (math.AG) ,Orbifold ,Mathematics - Abstract
Let $W\in \mathbb{C}[x_1,\cdots,x_N]$ be an invertible polynomial with an isolated singularity at origin, and let $G\subset {{\sf SL}}_N\cap (\mathbb{C}^*)^N$ be a finite diagonal and special linear symmetry group of $W$. In this paper, we use the category ${{\sf MF}}_G(W)$ of $G$-equivariant matrix factorizations and its associated VSHS to construct a $G$-equivariant version of Saito's theory of primitive forms. We prove there exists a canonical categorical primitive form of ${{\sf MF}}_G(W)$ characterized by $G_W^{{\sf max}}$-equivariance. Conjecturally, this $G$-equivariant Saito theory is equivalent to the genus zero part of the FJRW theory under LG/LG mirror symmetry. In the marginal deformation direction, we verify this for the FJRW theory of $\big(\frac{1}{5}(x_1^5+\cdots+x_5^5),\mathbb{Z}/5\mathbb{Z}\big)$ with its mirror dual B-model Landau-Ginzburg orbifold $\big(\frac{1}{5}(x_1^5+\cdots+x_5^5), (\mathbb{Z}/5\mathbb{Z})^4\big)$. In the case of the Quintic family $\mathcal{W}=\frac{1}{5}(x_1^5+\cdots+x_5^5)-\psi x_1x_2x_3x_4x_5$, we also prove a comparison result of B-model VSHS's conjectured by Ganatra-Perutz-Sheridan., Comment: 30 pages, comments welcome! Minor modification in V2
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- 2021
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12. DG-resolutions of NC-smooth thickenings and NC-Fourier–Mukai transforms
- Author
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Junwu Tu and Alexander Polishchuk
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Discrete mathematics ,Pure mathematics ,Functor ,General Mathematics ,Holomorphic function ,Mathematics::Geometric Topology ,Cohomology ,Coherent sheaf ,Mathematics::Algebraic Geometry ,Line bundle ,Torsion (algebra) ,Sheaf ,Sectional curvature ,Mathematics - Abstract
We give a construction of NC-smooth thickenings [a notion defined by Kapranov (J Reine Angew Math 505:73–118, 1998)] of a smooth variety equipped with a torsion free connection. We show that a twisted version of this construction realizes all NC-smooth thickenings as $$0$$ th cohomology of a differential graded sheaf of algebras, similarly to Fedosov’s construction in (J Differ Geom 40:213–238, 1994). We use this dg resolution to construct and study sheaves on NC-smooth thickenings. In particular, we construct an NC version of the Fourier–Mukai transform from coherent sheaves on a (commutative) curve to perfect complexes on the canonical NC-smooth thickening of its Jacobian. We also define and study analytic NC-manifolds. We prove NC-versions of some of GAGA theorems, and give a $$C^\infty $$ -construction of analytic NC-thickenings that can be used in particular for Kahler manifolds with constant holomorphic sectional curvature. Finally, we describe an analytic NC-thickening of the Poincare line bundle for the Jacobian of a curve, and the corresponding Fourier–Mukai functor, in terms of $$A_\infty $$ -structures.
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- 2014
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13. Homological Mirror Symmetry and Fourier–Mukai Transform
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Junwu Tu
- Subjects
Sheaf cohomology ,Pure mathematics ,Homological mirror symmetry ,Koszul duality ,General Mathematics ,Ideal sheaf ,Algebra ,Mathematics::Algebraic Geometry ,Local system ,Mathematics::K-Theory and Homology ,Sheaf ,Mathematics::Symplectic Geometry ,Symplectic manifold ,Symplectic geometry ,Mathematics - Abstract
We interpret symplectic geometry as certain sheaf theory by constructing a sheaf of curved A_\infty algebras which in some sense plays the role of a "structure sheaf" for symplectic manifolds. An interesting feature of this "structure sheaf" is that the symplectic form itself is part of its curvature term. Using this interpretation homological mirror symmetry can be understood by well-known duality theories in mathematics: Koszul duality or Fourier- Mukai transform. In this paper we perform the above constructions over a small open subset inside the smooth locus of a Lagrangian torus fibration. In a subsequent work we shall use the language of derived geometry to obtain a global theory over the whole smooth locus. However we do not know how to extend this construction to the singular locus. As an application of the local theory we prove a version of homological mirror symmetry between a toric symplectic manifold and its Landau-Ginzburg mirror.
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- 2013
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14. On the reconstruction problem in mirror symmetry
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Junwu Tu
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Pure mathematics ,53D37, 18G55 ,General Mathematics ,Fibration ,Holomorphic function ,Torus ,Moduli space ,Mathematics - Algebraic Geometry ,Mathematics::Algebraic Geometry ,Mathematics - Symplectic Geometry ,Rigid analytic space ,FOS: Mathematics ,Symplectic Geometry (math.SG) ,Gravitational singularity ,Locus (mathematics) ,Mirror symmetry ,Mathematics::Symplectic Geometry ,Algebraic Geometry (math.AG) ,Mathematics - Abstract
Let \pi: M \ra B be a Lagrangian torus fibration with singularities such that the fibers are of Maslov index zero, and unobstructed. The paper constructs a rigid analytic space M_0^\chk over the Novikov field which is a deformation of the semi-flat complex structure of the dual torus fibration over the smooth locus B_0 of \pi. Transition functions of M_0^\chk are obtained via A-\infty homomorphisms which capture the wall-crossing phenomenon of moduli spaces of holomorphic disks., Comment: Final version, minor changes. To appear in Advances in Mathematics
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- 2012
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15. PBW for an inclusion of Lie algebras
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Damien Calaque, Junwu Tu, Andrei Caldararu, Institut Camille Jordan [Villeurbanne] (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and ANR-08-JCJC-0096,Gésaq,Géométrie et structures algébriques quantiques(2008)
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Pure mathematics ,Non-associative algebra ,17B35, 17B55, 53C35 ,Adjoint representation ,Real form ,(g,K)-module ,01 natural sciences ,Representation theory ,Mathematics - Algebraic Geometry ,Representation of a Lie group ,0103 physical sciences ,Mathematics - Quantum Algebra ,FOS: Mathematics ,Quantum Algebra (math.QA) ,0101 mathematics ,Mathematics::Representation Theory ,Algebraic Geometry (math.AG) ,Mathematics ,Discrete mathematics ,Algebra and Number Theory ,010102 general mathematics ,Killing form ,Lie conformal algebra ,[MATH.MATH-QA]Mathematics [math]/Quantum Algebra [math.QA] ,010307 mathematical physics ,[MATH.MATH-AG]Mathematics [math]/Algebraic Geometry [math.AG] - Abstract
Let h \subset g be an inclusion of Lie algebras with quotient h-module n. There is a natural degree filtration on the h-module U(g)/U(g)h whose associated graded h-module is isomorphic to S(n). We give a necessary and sufficient condition for the existence of a splitting of this filtration. In turn such a splitting yields an isomorphism between the h-modules U(g)/U(g)h and S(n). For the diagonal embedding h \subset h \oplus h the condition is automatically satisfied and we recover the classical Poincae-Birkhoff-Witt theorem. The main theorem and its proof are direct translations of results in algebraic geometry, obtained using an ad hoc dictionary. This suggests the existence of a unified framework allowing the simultaneous study of Lie algebras and of algebraic varieties, and a closely related work in this direction is on the way., Major revision, proofs of several results rewritten. Added a section explaining the case of a general representation, as opposed to the trivial one. 20 pages, LaTeX
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- 2010
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16. Matrix factorizations via Koszul duality
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Junwu Tu
- Subjects
Pure mathematics ,Algebra and Number Theory ,Koszul duality ,Hochschild homology ,Mathematics::Commutative Algebra ,Mathematics::Rings and Algebras ,18E30, 14B05 ,K-Theory and Homology (math.KT) ,Mathematics - Rings and Algebras ,Mathematics::Algebraic Topology ,Mathematics - Algebraic Geometry ,Matrix (mathematics) ,Mathematics::K-Theory and Homology ,Rings and Algebras (math.RA) ,Mathematics - K-Theory and Homology ,Mathematics - Quantum Algebra ,FOS: Mathematics ,Quantum Algebra (math.QA) ,Algebraic Geometry (math.AG) ,Orbifold ,Mathematics - Abstract
In this paper we prove a version of curved Koszul duality for Z/2Z-graded curved coalgebras and their coBar differential graded algebras. A curved version of the homological perturbation lemma is also obtained as a useful technical tool for studying curved (co)algebras and precomplexes. The results of Koszul duality can be applied to study the category of matrix factorizations MF(R,W). We show how Dyckerhoff's generating results fit into the framework of curved Koszul duality theory. This enables us to clarify the relationship between the Borel-Moore Hochschild homology of curved (co)algebras and the ordinary Hochschild homology of the category MF(R,W). Similar results are also obtained in the orbifold case and in the graded case., Comment: Latex 34 pages, rewritten introduction, deleted an appendix, minor modification on proofs, final version
- Published
- 2010
- Full Text
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