arXiv subjects

Leilei Liu

Publications and source records attributed to Leilei Liu.

8 recordsLinked to original sources

arXiv2025

Shifted double Poisson structures and noncommutative Poisson extensions

We develop a theory of noncommutative Poisson extensions. For an augmented dg algebra $A$, we show that any shifted double Poisson bracket on $A$ induces a graded Lie algebra structure on the reduced cyclic homology. Under the Kontsevich--Rosenberg principle, we further prove that the noncommutative Poisson extension is compatible with noncommutative Hamiltonian reduction. Moreover, we show that shifted double Poisson structures are independent of the choice of cofibrant resolutions and that they induce shifted Poisson structures on the derived moduli stack of representations.

math.RT↗

arXiv2024

DG singular equivalence and singular locus

For a commutative Gorenstein Noetherian ring $R$, we construct an affine scheme $X$ solely from DG singularity category $S_{dg}(R)$ of $R$ such that there is a finite surjective morphism $X \rightarrow \mathrm{Spec}(R /I)$, where $\mathrm{Spec}(R /I)$ is the singular locus in $\mathrm{Spec}(R)$. As an application, for two such rings with equivalent DG singularity categories, we prove that the singular loci in their affine schemes have the same dimension.

math.AC↗

arXiv2023

Batalin-Vilkovisky algebra structure on Poisson manifolds with diagonalizable modular symmetry

We study the ``twisted" Poincaré duality of smooth Poisson manifolds, and show that, if the modular vector field is diagonalizable, then there is a mixed complex associated to the Poisson complex, which, combining with the twisted Poincaré duality, gives a Batalin-Vilkovisky algebra structure on the Poisson cohomology. This generalizes the previous results obtained by Xu for unimodular Poisson manifolds. We also show that the Batalin-Vilkovisky algebra structure is preserved under Kontsevich's deformation quantization, and in the case of polynomial algebras it is also preserved by Koszul duality.

math.DG↗

arXiv2022

Twisted bi-symplectic structure on Koszul twisted Calabi-Yau algebras

For a Koszul Artin-Schelter regular algebra (also called twisted Calabi-Yau algebra), we show that it has a "twisted" bi-symplectic structure, which may be viewed as a noncommutative and twisted analogue of the shifted symplectic structure introduced by Pantev, Toën, Vaquié and Vezzosi. This structure gives a quasi-isomorphism between the tangent complex and the twisted cotangent complex of the algebra, and may be viewed as a DG enhancement of Van den Bergh's noncommutative Poincaré duality; it also induces a twisted symplectic structure on its derived representation schemes.

math.RA↗

arXiv2021

Tilting objects in singularity categories of toric Gorenstein varieties

We study certain toric Gorenstein varieties with isolated singularities which are the quotient spaces of generic unimodular representations by the one-dimensional torus, or by the product of the one-dimensional torus with a finite abelian group. Based on the works of \v{S}penko and Van den Bergh [Invent. Math. 210 (2017), no. 1, 3-67] and Mori and Ueyama [Adv. Math. 297 (2016), 54-92], we show that the singularity categories of these varieties admit tilting objects, and hence are triangle equivalent to the perfect categories of some finite dimensional algebras.

math.AG↗

arXiv2019

Gravity algebra structure on the negative cyclic homology of Calabi-Yau algebras

In this paper, we study the gravity algebra structure on the negative cyclic homology or the cyclic cohomology of several classes of algebras. These algebras include: Calabi-Yau algebras, symmetric Frobenius algebras, unimodular Poisson algebras, and unimodular Frobenius Poisson algebras. The relationships among these gravity algebras are also discussed under some additional conditions.

math.RA↗

arXiv2019

Koszul duality and the Hochschild cohomology of Artin-Schelter regular algebras

We identify two Batalin-Vilkovisky algebra structures, one obtained by Kowalzig and Krahmer on the Hochschild cohomology of an Artin-Schelter regular algebra with semisimple Nakayama automorphism and the other obtained by Lambre, Zhou and Zimmermann on the Hochschild cohomology of a Frobenius algebra also with semisimple Nakayama automorphism, provided that these two algebras are Koszul dual to each other.

math.RA↗

arXiv2017

Compact bilateral single conductor surface wave transmission line

A compact bilateral single conductor surface wave transmission line (TL) is proposed, converting the quasi-transverse electromagnetic (QTEM) mode of low characteristic impedance slotline into the transverse magnetic (TM) mode of single-conductor TL. The propagation constant of the proposed TL is decided by geometric parameters of the periodic corrugated structure. Compared to conventional transitions between coplanar waveguide (CPW) and single-conductor TLs, such as Goubau line (G-Line) and surface plasmons TL, the proposed structure halves the size and this feature gives important potentials to develop integrated surface wave devices and circuits. The designed structure, sample fabrication and experimental verification are discussed.

physics.app-ph↗