papers

Publications (20)

math.CO2026

Grothendieck positivity for normal square root crystals

Eric Marberg, Kam Hung Tong, Tianyi Yu

Normal crystals (also known as Stembridge crystals) are commonly used to establish the Schur positivity of symmetric functions, as their characters are sums of Schur polynomials. I…

cs.LG2026

Listwise Direct Preference Optimization with Multi-Dimensional Preference Mixing

Yuhui Sun, Xiyao Wang, Zixi Li +6

Recent alignment methods based on Direct Preference Optimization (DPO) reformulate preference learning as supervised optimization over pairwise comparisons, offering improved effic…

math.CO2025

Grothendieck polynomials of inverse fireworks permutations

Chen-An Chou, Tianyi Yu

Pipedreams are combinatorial objects that compute Grothendieck polynomials. We introduce a new combinatorial object that naturally recast the pipedream formula. From this, we obtai…

math.CO2025

A positive combinatorial formula for the double Edelman--Greene coefficients

Jack Chen-An Chou, Tianyi Yu

Lam, Lee, and Shimozono introduced the double Stanley symmetric functions in their study of the equivariant geometry of the affine Grassmannian. They proved that the associated dou…

math.CO2024

Tableau formula for vexillary double Edelman--Greene coefficients

Adam Gregory, Zachary Hamaker, Tianyi Yu

Lam, Lee and Shimozono recently introduced backstable double Grothendieck polynomials to represent -theory classes of the infinite flag variety. They used them to define double…

math.CO2021

Grothendieck to Lascoux expansions

Mark Shimozono, Tianyi Yu

We establish the conjecture of Reiner and Yong for an explicit combinatorial formula for the expansion of a Grothendieck polynomial into the basis of Lascoux polynomials. This expa…

cs.DC2022

A Creativity Survey of Parallel Sorting Algorithm

Tianyi Yu, Wei Li

Sorting is one of the most fundamental problems in the field of computer science. With the rapid development of manycore processors, it shows great importance to design efficient p…

math.CO2023

Lascoux expansion of the product of a Lascoux and a stable Grothendieck

Gidon Orelowitz, Tianyi Yu

This paper gives a tableau formula for expanding the product of a Lascoux polynomial and a stable Grothendieck polynomial into Lascoux polynomials. Lascoux and stable Grothendieck…

math.CO2023

Top-degree components of Grothendieck and Lascoux polynomials

Jianping Pan, Tianyi Yu

The Castelnuovo-Mumford polynomial with is the highest homogeneous component of the Grothendieck polynomial . Pechenik, Speye…

math.CO2020

Harmonic bases for generalized coinvariant algebras

Brendon Rhoades, Tianyi Yu, Zehong Zhao

Let be nonnegative integers and let be a partition of . S. Griffin recently introduced a quotient of the polynomial ring

math.CO2023

Constructing maximal pipedreams of double Grothendieck polynomials

Chen-An Chou, Tianyi Yu

Pechenik, Speyer and Weigandt defined a statistic on permutations which characterizes the leading monomial in top degree components of double Grothendieck…

math.CO2022

A bijection between -Kohnert diagrams and reverse set-valued tableaux

Jianping Pan, Tianyi Yu

Lascoux polynomials are -theoretic analogues of the key polynomials. They both have combinatorial formulas involving tableaux: reverse set-valued tableaux () rule…

math.CO2024

Embedding bumpless pipedreams as Bruhat chains

Tianyi Yu

Schubert polynomials are distinguished representatives of Schubert cycles in the cohomology of the flag variety. In the spirit of Bergeron and Sottile, we use the Bruhat order to g…

math.CO2024

Connection between Schubert polynomials and top Lascoux polynomials

Tianyi Yu

Schubert polynomials form a basis of the polynomial ring. This basis and its structure constants have received extensive study. Recently, Pan and Yu initiated the study of top Lasc…

math.CO2023

Constructing a Gröbner basis of Griffin's ideal

Tianyi Yu

In his Ph.D. thesis, Sean Griffin introduced a family of ideals and found monomial bases for their quotient rings. These rings simultaneously generalize the Delta Conjecture coinva…

cs.LG2022

Federated Graph-based Networks with Shared Embedding

Tianyi Yu, Pei Lai, Fei Teng

Nowadays, user privacy is becoming an issue that cannot be bypassed for system developers, especially for that of web applications where data can be easily transferred through inte…

math.CO2024

Marked Bumpless Pipedreams and Compatible Pairs

Daoji Huang, Mark Shimozono, Tianyi Yu

We construct a bijection between marked bumpless pipedreams with reverse compatible pairs, which are in bijection with not-necessarily-reduced pipedreams. This directly unifies var…

math.CO2022

Set-valued tableaux rule for Lascoux polynomials

Tianyi Yu

Lascoux polynomials generalize Grassmannian stable Grothendieck polynomials and may be viewed as K-theoretic analogs of key polynomials. The latter two polynomials have combinatori…

math.CO2024

A row analogue of Hecke column insertion

Daoji Huang, Mark Shimozono, Tianyi Yu

We introduce a new row insertion algorithm on decreasing tableaux and increasing tableaux, generalizing Edelman-Greene (EG) row insertion. Our row insertion algorithm is a nontrivi…

cs.AI2026

MirrorCraft: Paired Evaluation under Hidden Rule Changes in Minecraft

Jianxin Gao, Beini Hu, Runze Li +6

With the prosperity of the large language models (LLMs), it has become an interesting topic: how do LLM-based agents work in Minecraft? Unfortunately, most existing benchmarks eval…