activity
20042026
most citedBinary quadratic forms and ray class groups

11 citations · 20 across the 35 of their papers we have counts for

collaborators

47 papers

math.NT2026

Adelic framed form class groups and explicit class field theory

Ja Kyung Koo, Dong Hwa Shin, Dong Sung Yoon

Let be a negative discriminant, and let . Let denote the set of primitive positive definite binary quadratic forms over of…

math.NT2026

On the integrality of modular functions over and Kronecker-type congruences

Ho Yun Jung, Ja Kyung Koo, Dong Hwa Shin

Let be a positive integer and let be a meromorphic modular function of level with rational Fourier coefficients. For a prime , define a function on the complex…

math.NT2025

A simplified algorithmic realization of Galois actions on special values of modular functions

Ja Kyung Koo, Dong Hwa Shin, Dong Sung Yoon

We propose an explicit and practical algorithm for computing Galois conjugates and irreducible polynomials for special values of modular functions evaluated at CM points associated…

math.NT2025

Inverse limits of CM points on certain Shimura varieties

Ho Yun Jung, Ja Kyung Koo, Dong Hwa Shin

Let be a positive integer, and let or $1\Mod{4}$ be a negative integer. We define the sets and as subsets…

math.NT2023

Gauss's form class groups and Shimura's canonical models

Ja Kyung Koo, Dong Hwa Shin, Dong Sung Yoon

Let be a positive integer and be a subgroup of containing . Let be an imaginary quadratic field and be an order of dis…

math.NT2023

Class fields and form class groups for solving certain quadratic Diophantine equations

Ho Yun Jung, Ja Kyung Koo, Dong Hwa Shin +1

Let be an imaginary quadratic field and be an order in . We construct class fields associated with form class groups which are isomorphic to certain $\mathcal{…