J. Koo

activity

20042026

most citedBinary quadratic forms and ray class groups

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

collaborators

Showing 2012Show all

4 papers · 1 filter

math.NT2012

Application of Weierstrass units to relative power integral bases

Ho Yun Jung, Ja Kyung Koo, Dong Hwa Shin

Let $K$ be an imaginary quadratic field other than $Q (- 1)$ and $Q (- 3)$ . We construct relative power integral bases between certain abelian extension…

math.NT2012

Some applications of modular units

Ick Sun Eum, Ja Kyung Koo, Dong Hwa Shin

We show that a weakly holomorphic modular function can be written as a sum of modular units of higher level. We further find a necessary and sufficient condition for a Siegel modul…

math.NT2012★ 1 cited

Construction of class fields over cyclotomic fields

Ja Kyung Koo, Dong Sung Yoon

Let $ℓ$ and $p$ be odd primes. For a positive integer $μ$ let $k_{μ}$ be the ray class field of $k = Q (e^{2 π i / ℓ})$ modulo $2 p^{μ}$ . We present certain class fields $K_{μ}$ o…

math.NT2012★ 1 cited

On some theta constants and class fields

Ja Kyung Koo, Dong Hwa Shin

We first find a sufficient condition for a product of theta constants to be a Siegel modular function of a given even level. And, when $K_{(2 p)}$ denotes the ray class field of $K=…