Skip to main content

Sanghoon Baek

Korea Advanced Institute of Science and Technology · Mathematics

About the Lab

Professor Sanghoon Baek's research lab specializes in microbial taxonomy and systematics, with a focus on the isolation, characterization, and phylogenetic classification of novel bacterial species from diverse environments such as ginseng fields and freshwater sediments. The lab employs polyphasic approaches combining 16S rRNA gene sequencing, genomic DNA G+C content analysis, and chemotaxonomic characterization to delineate new taxa within genera like *Brevibacillus*, *Paenibacillus*, and *Novosphingobium*. In parallel, the lab conducts advanced research in algebraic geometry and Galois cohomology, particularly on the essential dimension of central simple algebras and invariants of algebras of low degree and exponent 2. This dual focus bridges microbiology and abstract algebra, reflecting a unique integration of biological and mathematical research.

bacterial taxonomy16S rRNA sequencingcentral simple algebrasessential dimensionGalois cohomology

Research Overview

Papers
61
Total Citations
387
Papers (5y)
12
Primary Field
Mathematics

Research Output Trend

Figures are computed from collected data and may differ slightly.

Publications per year (5y)
12total
2020
2021
2022
2023
2025
Citations per year (5y)
3total
20202021202220232025

Selected Papers

15
1
Article|38 citations·2010
Tumebacillus ginsengisoli sp. nov., isolated from soil of a ginseng field
Sanghoon Baek, Yingshun Cui, Sun‐Chang Kim, Chang-Hao Cui, Chengri Yin, Sung‐Taik Lee, Wan‐Taek Im
SJR Q1INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY

A gram-reaction-positive, rod-shaped, spore-forming bacterium, designated Gsoil 1105(T), was isolated from soil of a ginseng field in Pocheon Province in South Korea and characterized in order to determine its taxonomic position. Comparative analysis of the 16S rRNA gene sequence showed that the isolate belongs to the order Bacillales, showing the highest level of sequence similarity with respect to Tumebacillus permanentifrigoris Eur1 9.5(T) (94.6 %). The phylogenetic distances from other descr

Molecular BiologyBiochemistry, Genetics and Molecular Biology
2
Article|38 citations·2006
Brevibacillus ginsengisoli sp. nov., a denitrifying bacterium isolated from soil of a ginseng field
Sanghoon Baek, Wan‐Taek Im, Hyun Woo Oh, Jung‐Sook Lee, Hee‐Mock Oh, Sung‐Taik Lee
SJR Q1INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY

A Gram-positive, rod-shaped, spore-forming bacterium, Gsoil 3088T, was isolated from soil from a ginseng field in Pocheon Province in South Korea and characterized in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 3088T was shown to belong to the family Paenibacillaceae, being related to Brevibacillus centrosporus (96.6%), Brevibacillus borstelensis (96.3%), Brevibacillus parabrevis (96.1%), Brevibacillus formosus (96.1%), Brevibacillus

Molecular BiologyBiochemistry, Genetics and Molecular Biology
3
Article|34 citations·2010
Novosphingobium sediminicola sp. nov. isolated from freshwater sediment
Sanghoon Baek, Ju Hyoung Lim, Long Jin, Hyung-Gwan Lee, Sung‐Taik Lee
SJR Q1INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY

A yellow-pigmented, Gram-negative, short rod-shaped, non-motile and non-spore-forming bacterial strain, designated HU1-AH51(T), was isolated from freshwater sediment and was characterized using a polyphasic approach, in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain HU1-AH51(T) was shown to belong to the genus Novosphingobium, showing the highest level of sequence similarity with respect to Novosphingobium resinovorum NCIMB 8767(T) (96.0 %),

Molecular BiologyBiochemistry, Genetics and Molecular Biology
4
Article|19 citations·2009
Paenibacillus pocheonensis sp. nov., a facultative anaerobe isolated from soil of a ginseng field
Sanghoon Baek, Tae‐Hoo Yi, Sung‐Taik Lee, Wan‐Taek Im
SJR Q1INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY

A Gram-positive, aerobic or facultatively anaerobic, rod-shaped, spore-forming bacterium, strain Gsoil 1138(T), was isolated from soil of a ginseng field in Pocheon Province, South Korea, and was characterized in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence analysis, strain Gsoil 1138(T) was shown to belong to the family Paenibacillaceae and was most closely related to the type strains of Paenibacillus chondroitinus (98.2 % similarity) and Paenibacillus algin

Molecular BiologyBiochemistry, Genetics and Molecular Biology
5
Article|18 citations·2012
Essential dimension of central simple algebras
Sanghoon Baek, Alexander Merkurjev
SJR Q1Acta MathematicaOA

Let p be a prime integer, 1≤s≤r be integers and F be a field of characteristic different from p. We find upper and lower bounds for the essential p-dimension edp($ Al{{g}_{{{{p}^r},{{p}^s}}}} $) of the class $ Al{{g}_{{{{p}^r},{{p}^s}}}} $ of central simple algebras of degree pr and exponent dividing ps. In particular, we show that ed(Alg8,2)=ed2(Alg8,2)=8 and edp($ Al{{g}_{{{{p}^2},p}}} $)=p2+p for p odd.

Discrete Mathematics and CombinatoricsMathematics
6
Article|14 citations·2009
Invariants of simple algebras
Sanghoon Baek, Alexander Merkurjev
SJR Q2manuscripta mathematicaOA

We determine the group of invariants with values in Galois cohomology with coefficients $${\mathbb{Z}/2\mathbb{Z}}$$ of central simple algebras of degree at most 8 and exponent dividing 2.

Geometry and TopologyMathematics
7
Article|9 citations·2009
Sphingobium vulgare sp. nov., isolated from freshwater sediment
Sanghoon Baek, Ju Hyoung Lim, Sung‐Taik Lee
SJR Q1INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY

A Gram-negative, motile, non-spore-forming bacterial strain, designated HU1-GD12(T), was isolated from freshwater sediment. The strain was characterized by using a polyphasic approach in order to determine its taxonomic position. Comparative analysis of the 16S rRNA gene sequence showed that the isolate constituted a distinct branch within the genus Sphingobium, showing the highest level of sequence similarity with respect to Sphingobium ummariense RL-3(T) (96.2 %). Strain HU1-GD12(T) had a geno

Molecular BiologyBiochemistry, Genetics and Molecular Biology
8
Article|9 citations·2011
Essential dimension of simple algebras in positive characteristic
Sanghoon Baek
SJR Q2Comptes Rendus MathématiqueOA

Let p be a prime integer. For any integers <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1</mml:mn> <mml:mo>⩽</mml:mo> <mml:mi>s</mml:mi> <mml:mo>⩽</mml:mo> <mml:mi>r</mml:mi> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mtext/> <mml:mrow> <mml:msup> <mml:mi>p</mml:mi> <mml:mi>r</mml:mi> </mml:msup> <mml:mo>,</mml:mo> <mml:msup> <mml:mi>p</mml:mi> <mml:mi>s</mml:mi> </mml:msup> </mml:mrow> </mml:ms

Geometry and TopologyMathematics
9
Article|8 citations·2016
Chow groups of products of Severi-Brauer varieties and invariants of degree 3
Sanghoon Baek
SJR Q1Transactions of the American Mathematical SocietyOA

We study the semi-decomposable invariants of a split semisimple group and their extension to a split reductive group by using the torsion in the codimension <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="2"> <mml:semantics> <mml:mn>2</mml:mn> <mml:annotation encoding="application/x-tex">2</mml:annotation> </mml:semantics> </mml:math> </inline-formula> Chow groups of a product of Severi-Brauer varieties. In particular, for any <inline

Geometry and TopologyMathematics
10
Preprint|8 citations·2011
Basic polynomial invariants, fundamental representations and the Chern class map
Sanghoon Baek, Erhard Neher, Kirill Zainoulline
arXiv (Cornell University)OA

Consider a crystallographic root system together with its Weyl group $W$ acting on the weight lattice $M$. Let $Z[M]^W$ and $S^*(M)^W$ be the $W$-invariant subrings of the integral group ring $Z[M]$ and the symmetric algebra $S^*(M)$ respectively. A celebrated theorem of Chevalley says that $Z[M]^W$ is a polynomial ring over $Z$ in classes of fundamental representations $w_1,...,w_n$ and $S^*(M)^{W}$ over rational numbers is a polynomial ring in basic polynomial invariants $q_1,...,q_n$, where $

Geometry and TopologyMathematics
11
Article|7 citations·2011
Essential dimension of simple algebras with involutions
Sanghoon Baek
SJR Q1Bulletin of the London Mathematical SocietyOA

Let 1⩽m⩽n be integers with m|n and Algn, m the class of central simple algebras of degree n and exponent dividing m. In this paper, we find new, improved upper bounds for the essential dimension and two-dimension of Algn, 2. In particular, we show that ed2(Alg16, 2)=24 over a field F of characteristic different from 2.

Geometry and TopologyMathematics
12
Article|5 citations·2013
On the torsion of Chow groups of twisted spin-flags
Sanghoon Baek, Kirill Zainoulline, Changlong Zhong
SJR Q1Mathematical Research LettersOA

In the present paper, we provide a uniform bound for the annihilators of torsion of Chow groups of the variety of Borel subgroups of a strongly inner linear algebraic group of orthogonal type.

Geometry and TopologyMathematics
13
Article|5 citations·2015
On the torsion of Chow groups of Severi-Brauer varieties
Sanghoon Baek
SJR Q1Israel Journal of Mathematics
Geometry and TopologyMathematics
14
Article|5 citations·2015
Semiorthogonal decompositions for twisted grassmannians
Sanghoon Baek
SJR Q1Proceedings of the American Mathematical SocietyOA

In this article, we present semiorthogonal decompositions for twisted forms of grassmannians.

Algebra and Number TheoryMathematics
15
Article|5 citations·2017
The K -Theory of Versal Flags and Cohomological Invariants of Degree 3
Sanghoon Baek, Rostislav Devyatov, Kirill Zainoulline
SJR Q1Documenta MathematicaOA

Let G be a split semisimple linear algebraic group over a field and let X be a generic twisted flag variety of G . Extending the Hilbert basis techniques to Laurent polynomials over integers we give an explicit presentation of the Grothendieck ring K_0(X) in terms of generators and relations in the case G=G^{sc}/\mu_2&gt; is of Dynkin type A or C (here G^{sc} is the simply-connected cover of G ); we compute various groups of (indecomposable, semi-decomposable) cohomological invariants of degree

Geometry and TopologyMathematics

Research Areas

Geometry and TopologyMolecular BiologyDiscrete Mathematics and CombinatoricsMathematical PhysicsAlgebra and Number TheoryPlant Science

Dive deeper into Sanghoon Baek's research on Nubint

Open this lab's papers in the app to read with AI, summarize, and cite in your writing.