On November 11, 2020, Meike Hatzel from Technische Universität Berlin gave an online talk on the existence of a bramble of small order and small size in a graph of tree-width k at the Virtual Discrete Math Colloquium. The title of her talk was “Constant congestion bramble“.

## Casey Tompkins gave a talk on extremal problems on Boolean and linear lattices with forbidden posets at the Discrete Math Seminar

On November 10, 2020, Casey Tompkins from the IBS Discrete Mathematics Group presented a talk on the extremal problems on Boolean and linear lattices with forbidden posets at the Discrete Math Seminar. The title of his talk was “Extremal forbidden poset problems in Boolean and linear lattices“.

## 2020-2 Call for IBS Young Scientist Fellowship (Due: December 13, 2020)

## Note: IBS Discrete Mathematics Group also has an opening for a postdoctoral fellowship.

#### 1. Purpose and Background

With the vision of **“Making Discoveries for Humanity and Society,”** the Institute for Basic Science (IBS) was founded in 2011 by the Korean government to promote basic science in Korea. To date, IBS has 31 Research Centers and each Center has been yielding outstanding results in various research fields.

The **IBS “Young Scientist Fellowship”** started in 2016 to play an active role in fostering the next generation of basic science leaders. We believe this Fellowship offers junior scientists opportunities to conduct independent research by utilizing state-of-the-art infrastructure and to grow on the basis of research collaborations with leading researchers.

We hope that the **Fellowship** serves as a **stepping stone** for our researchers to mature into leading researchers in basic science.

#### 2. Eligibility

Within 7 years of obtaining a Ph.D. (obtained no earlier than 1 January 2013) or under the age of 40 with a Ph.D. (born no earlier than 1 January 1980)

※ Ph.D. candidates must be conferred with Ph.D. degrees before February 28, 2021.

※ Current IBS researchers are eligible to apply, if they meet the above criteria.

#### 3. Recruiting Research Center and Number of Openings

**Discrete Mathematics Group has an opening** for 1 YSF.

For other centers and groups, please visit the IBS website https://www.ibs.re.kr/ysf/.

※ The final number of openings may change depending on the circumstances of IBS.

#### 4. Benefit and Condition

**Full-time work and 100% research participation in principle**

※ If successful candidates have been also selected for another institute’s research project (e.g. Sejong Science Fellowship, Young Researcher Program of National Research Foundation), their selection may be cancelled.- Annual budget of KRW 150–300 mil. per year, including salary of KRW 60–70 mil. (up to KRW 150 mil. for theoretical fields and up to KRW 300 mil. for experimental fields)
- Appointment for three years with a possible two-year extension depending on the performance review results

※ When current IBS researchers are selected as a Young Scientist Fellow (YSF) of their Center, support will be offered for up to three years. Please refer to the FAQ for details. - After physically relocated to one of the IBS Centers, YSFs will conduct independent research by utilizing research facilities and equipment of the Center. YSFs may organize a small research group.
**Selected YSFs must be appointed and commence their research within 2021.**

※ If their appointment and research commencement processes are not completed within 2021, their selection may be cancelled.

#### 5. Selection Process: Three Steps

- Letter of Intent (approx. 3 pages)
- Submission deadline: by
**December 13, 2020** - Review by directors and evaluation panel members
- Invitation to submit full proposals: by January 15, 2021

- Submission deadline: by
- Full Proposal (approx. 10 pages)
- Submission deadline: by
**February 14, 2021** - Review by directors and evaluation panel members
- Invitation for an on-site interview: by March 2021

- Submission deadline: by
- Interview
- On-site Interview and presentation: in
**March 2021** - Comprehensive review by evaluation panel chairs
- Announcement of YSFs: by late April 2021

- On-site Interview and presentation: in

#### 6. How to Apply

Apply via the IBS website at http://www.ibs.re.kr/ysf/apply by **December 13, 2020 (KST)**.

#### 7. Inquiries

Talent Acquisition and Development Team at ysf@ibs.re.kr or IBS homepage at https://www.ibs.re.kr/ysf

## Daniel Cranston gave a talk on partitioning the vertex set of a graph into an edge-less graph and a forest consisting of small components at the Virtual Discrete Math Colloquium

On November 5, 2020, Daniel Cranston from Virginia Commonwealth University gave a talk on the condition of the maximum average degree for a graph to have a partition of its vertex set into an independent set and a set inducing a forest consisting of components of small size at the Virtual Discrete Math Colloquium. The title of his talk was “Vertex Partitions into an Independent Set and a Forest with Each Component Small“.

## Jaeseong Oh (오재성) gave a talk on the condition of ribbon graphs sharing the same delta-matroid at the Discrete Math Seminar

On November 3, 2020, Jaeseong Oh (오재성) from Seoul National University presented his work with Iain Moffatt on the characterization of ribbon graphs having the same delta-matroid. The title of his talk is “A 2-isomorphism theorem for delta-matroids“.

## Jeong Ok Choi (최정옥) presented a talk on the contagion game and the network creation game on graphs at the Discrete Math Seminar

On October 27, 2020, Jeong Ok Choi (최정옥) from IBS Discrete Mathematics Group / GIST gave a talk on some game-theoretic problems on graphs, more specifically on the contagion game and the network creation game. The title of her talk was “Various game-theoretic models on graphs“.

## Chun-Hung Liu (劉俊宏) gave a talk on his recent results on the asymptotic dimension of families of various graph classes at the Virtual Discrete Math Colloquium

On October 22, 2020, Chun-Hung Liu (劉俊宏) from Texas A&M University gave a talk on his recent work answering several open problems on the asymptotic dimension of several graph classes at the Virtual Discrete Math Colloquium. The title of his talk was “Asymptotic dimension of minor-closed families and beyond“.

## Joonkyung Lee (이준경) gave a talk on norms defined from graphs at the Discrete Math Seminar

On October 21, 2020, Joonkyung Lee (이준경) from University College London gave a talk at the Discrete Math Seminar on norms defined from graphs motivated by Sidorenko’s conjecture and Gowers norms on extremal combinatorics, unifying two seemingly different concepts of real-norming graphs and complex-norming graphs. The title of his talk was “On graph norms for complex-valued functions“. Joonkyung Lee will stay at the IBS discrete mathematics group for several weeks from October 19.

## The IBS Discrete Mathematics Group (DIMAG) Postdoctoral Research Fellowship (Due: December 5, 2020)

The IBS Discrete Mathematics Group (DIMAG) in Daejeon, Korea invites applications for one postdoctoral research fellowship position.

URL: https://dimag.ibs.re.kr/hiring/

DIMAG is a research group that was established in December 1, 2018 at the Institute for Basic Science (IBS), led by Prof. Sang-il Oum. DIMAG is located at the headquarters of the Institute for Basic Science (IBS) in Daejeon, South Korea, a city of 1.5 million people.

The position is available for individuals who are within the first five years after obtaining their Ph.D at the date of appointment or be expected to obtain a Ph.D within three months from the date of appointment. Successful candidates for postdoctoral research fellowship positions will be new or recent Ph.D.’s with outstanding research potential in all fields of **discrete mathematics** with emphasis on **structural graph theory, extremal graph theory, combinatorial optimization, matroid theory, or fixed-parameter tractable algorithms**.

This appointment is for two years, and the starting salary is no less than KRW 57,000,000. The appointment is one time renewable up to 3 years in total contingent upon the outstanding performance of the researcher. The expected appointment date is September 1, 2021. This is a purely research position and will have no teaching duties.

A complete application packet should include:

- AMS standard cover sheet (preferred) or cover letter (PDF format)
- Curriculum vitae including a publication list (PDF format)
- Research statement (PDF format)
- Consent to Collection and Use of Personal Information (PDF file)
- At least 3 recommendation letters

For full consideration, applicants should email items 1, 2, 3, and 4 and arrange their recommendation letters emailed to **dimag@ibs.re.kr** by **December 5, 2020, Saturday**.

Recommendations letters forwarded by an applicant will not be considered.

DIMAG encourages applications from individuals of diverse backgrounds.

*In the unlikely event of closing the Center, the employment contract will be terminated accordingly. For Korean citizens who have not yet completed their military duty: IBS는 병역특례지정기관입니다. IBS is a designated institute for alternative military service.*

## Minki Kim (김민기) gave a talk on the collapsibility of the complex of vertex sets not containing independent sets of fixed size at the Discrete Math Seminar

On September 29, 2020, Minki Kim (김민기) from the IBS Discrete Mathematics Group presented his work on the collapsibility of the complex $I_n(G)$ of vertex sets of a graph $G$ not containing any $n$-vertex independent set at the Discrete Math Seminar. The title of his talk was “Complexes of graphs with bounded independence number“.