Pham Hung Quy

activity

20162022

collaborators

11 papers

math.AC2022

On the Frobenius closure of parameter ideals when the ring is F-injective on the punctured spectrum

Duong Thi Huong, Pham Hung Quy

Let $(R, m)$ be an excellent generalized Cohen-Macaulay local ring of dimension $d$ that is $F$ -injective on the punctured spectrum. Let $q$ be a standard parameter idea…

math.NT2021

A Note on Je{ś}manowicz' Conjecture for Non-primitive Pythagorean Triples

Van Thien Nguyen, Viet Kh. Nguyen, Pham Hung Quy

Let $(a, b, c)$ be a primitive Pythagorean triple parameterized as $a = u^{2} - v^{2}, b = 2 uv, c = u^{2} + v^{2}$ ,\ where $u > v > 0$ are co-prime and not of the same parity. In 1956, L. Je{ś}manowic…

math.AC2021

Frobenius test exponent for ideals generated by filter regular sequences

Duong Thi Huong, Pham Hung Quy

Let $(R, m)$ be a Noetherian local ring of prime characteristic $p > 0$ , and $t$ an integer such that $H_{m}^{j} (R) / 0_{H_{m}^{j} (R)}^{F}$ has finite length for all $j < t$ .…

math.AC2019

Asymptotic Lech's inequality

Craig Huneke, Linquan Ma, Pham Hung Quy +1

We explore the classical Lech's inequality relating the Hilbert--Samuel multiplicity and colength of an $m$ -primary ideal in a Noetherian local ring $(R, m)$ .…

math.AC2019

Filter regular sequence under small perturbations

Linquan Ma, Pham Hung Quy, Ilya Smirnov

We answer affirmatively a question of Srinivas--Trivedi: in a Noetherian local ring $(R, m)$ , if $I = (f_{1}, \dots, f_{r})$ is an ideal generated by a filter-regular sequence an…

math.AC2019

On the index of reducibility of parameter ideals: The stable and limit values

Nguyen Tu Cuong, Pham Hung Quy

Let $(R, m)$ be a Noetherian local ring and $M$ a finitely generated $R$ -module of dimension $d$ . A famous result of Northcott says that if $M$ is Cohen-Macaulay, then the in…