JOHAN SAMSING

Assistant Professor. Niels Bohr International Academy.

Contact: jsamsing@gmail.com

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Theoretical Astrophysicist

I am Louis-Hansen Assistant Professor, Villum-Young Investigator (PI of a 1.6 million $ grant), and Marie Curie Fellow, at the Niels Bohr International Academy (NBIA) in Copenhagen, Denmark. Before joining the Niels Bohr Institute I was Einstein/Spitzer Fellow at Princeton University (see Short BIO below).

Currently, my research interests lie in the new field of Gravitational Wave Astrophysics. I am particular interested in finding new ways of probing the astrophysical origin of binary black hole mergers observable by LIGO/Virgo/KAGRA, and future LISA and Deci-Hetz detectors.

My first-author papers in this field alone have already >800 citations, where >75% of these have been written together with only fellow students and/or postdocs.

The COVID-19 year(s) have not provided the best working conditions for a lot of people including myself. But let's all hope for a productive and healthy 2021, when we can all meet again! Until then, stay safe.

Short BIO

2014-2017: Princeton - Einstein Fellow. 2015-2018: Princeton Society of Fellows. 2018-2019: Princeton - Lyman Spitzer Fellow. 2019-2024: NBIA - Louis-Hansen Ass. Prof. 2019-2021: NBIA - Marie Curie Fellow. 2019-2024: NBIA - Villum-Young Investigator (1.6 million $ grant - see more in News below)

Advised/Co-advised several undergraduate and graduate students from around the world.

RESEARCH

Research:

My current research is centered on the key question of how binary black hole mergers form in our Universe. In particular, I study dynamical formation where black hole binaries are paired up through chaotic multi-body interactions in dense stellar systems. For this, I have developed both novel analytical and numerical tools that have led to several highly-cited breakthroughs, as outlined below.

My main results relate to the formation of eccentric black hole mergers, which I have proven are a natural outcome of dynamical formation. Together with mass and spin, eccentricity now constitute one of the key parameters that we can use to constrain the astrophysical formation environment of the growing set of GW sources.

Scientific Contributions:

  • ADS-LINK: First statistical solution to the chaotic 3-body problem with GR.

  • ADS-LINK: First derivation of how eccentric LIGO mergers form in clusters.

  • ADS-LINK: First derivation of the formation of eccentric LISA sources in clusters.

  • ADS-LINK: A possible origin of GW190521?

Publications:

A link to all my publications can be found here: NASA-ADS

NEWS & EVENTS

  • Jan 2021: GW group at the NBIA now complete!! Dan D'Orazio. Johan Samsing. Bin Liu. (see picture below)

  • Dec 2020: "Black Holes Link up in Strange Ways": In the NEWS with Dan D'Orazio (article)

  • Nov 2020: Organized "Newest Results from LIGO/Virgo/KAGRA" with Dan D'Orazio (website).

  • Jan 2020: Main Organizer of the "2. Gravitational Wave Meeting in Denmark" (website)

  • Jan 2020: Awarded a 1.6 million $ grant and appointed "Villum-Young Investigator" (website)

  • Aug 2019: Co-organized: "Current Themes in Gravitational Physics" (website)

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TALKS & ACTIVITIES

Talks:

  • Harvard, cfa, USA (April. 2021).

  • Ben-Gurion University, Israel (Nov. 2020).

  • University of Birmingham (Nov. 2020).

  • LISA Symposium XIII (Aug. 2020).

  • Leiden University, Netherlands (April 2020).

  • Nagoya University, Japan (oct. 2019).

  • Yukawa Inst., Kyoto, Japan (oct. 2019).

  • Niels Bohr Inst., Denmark (aug. 2019).

  • New York University, NYC (spring 2019).

  • Gravity Initiative, Princeton (Feb. 25 2019).

  • Black Hole Initiative, Harvard (29. Jan. 2019).

  • U. Maryland (26. Nov. 2018).

  • Stony Brook, NYC (19. Nov. 2018).

  • RIT, Rochester (9. Nov. 2018).

  • CITA, Toronto (22. Oct. 2018).

  • IAS, Princeton (13.September 2018).

  • Harvard, CfA (11.September 2018).

  • LIGO collaboration (July 2018).

  • Niels Bohr Institute (NBI) (June 2018).

  • Princeton Center for Theoretical Sciences (spring 2018)

  • John Hopkins University (spring 2018)

  • CCA, NYC (March 2018).

  • Columbia University (March 2018).

  • University of Kobe, RIKEN (January 2018).

  • University of Osako, (January 2018).

  • University of Tokyo, (January 2018).

  • CCA, NYC, Few-body scattering meeting (fall 2017).

  • IAS, Princeton, leading several informal discussions (fall 2017).

  • Caltech, seminar (fall 2017)

  • UC Santa Cruz, N-body meeting (fall 2017).

  • KIPAC, Stanford (fall 2017).

  • Cornell, seminar (fall 2017).

  • cfa, Harvard, Einstein symposium (fall 2017).

  • Princeton Society of Fellows, seminar (fall 2017)

  • Niels Bohr Institute, Kavli summer school (summer 2017)

  • University of the Virgin Islands (summer 2017).

  • Princeton Society of Fellows, seminar (spring 2017)

  • Thunch, Princeton (spring 2017).

  • Gravity group, Princeton (winter 2017).

  • Peyton hall Observatory, Princeton (winter 2017).

  • Columbia, seminar (fall 2016).

  • cfa, Harvard, Einstein symposium (fall 2016).

  • MODEST-16 workshop, AMNH, (fall 2016).

  • Columbia University, seminar (fall 2016).


Activities:

  • Organized with D. D'Orazio: "Rapid Fire O3 LIGO/Virgo Workshop" (Nov 2020)

  • Main-organizer: "2nd Gravitational Wave meeting in Denmark" (Jan 2020)

  • Lorentz Center, "Black Hole Mergers and Gravitational Waves". (Dec. 2019).

  • Co-organized: "Current Themes in Gravitational Physics", NBI. (Aug. 2019).

  • Aspen, USA (Feb. 2019).

  • CIERA, Northwestern U. (dec. 2018).

  • JSI-GWPAW 2018, Washington (dec. 2018).

  • Sackler Conf. at Harvard on Gravitational Waves and LIGO.

  • PCTS Gravitational Waves Meeting.

  • Co-organized N-body meeting CCA, NYC (1 week, fall 2017).

  • IAS, Princeton, meeting on the galactic center (3 days, fall 2017).

  • UC Santa Cruz, N-body meeting (1 week, fall 2017).

  • AMNH, NYC (fall 2017)

  • Columbia university, workshop on merging neutron stars (fall 2017).

  • Interviewed for full page article in Jyllands Posten (fall 2017).

  • Polish Academy of Sciences, Warsaw (1 week, fall 2017).

  • Mentoring students at Kavli summer school (6 weeks, summer 2017).

  • Finalist in `Art of Science' competition, Princeton, (spring 2017).

  • Aspen CTP, winter school on gravitational waves (10 days, winter 2017).

  • Mentoring student on Junior paper (fall 2016).

  • Mentoring student at USRP, Princeton University (7 weeks, summer 2016).

  • Co-organized the program USRP, Princeton University (7 weeks, summer 2016).

  • LIGO workshop, "Compact Binary Mergers", Columbia University (winter 2016).

  • UC Santa Cruz, (4 weeks, Summer 2016).

  • UC Santa Cruz, (1 week, spring 2016).

  • IPMU, Japan, (4 weeks, winter 2016).

  • CfA Harvard, Boston, (1 weeks, summer 2015).

  • CfA Harvard, Boston, (2 weeks, spring 2015).

  • Aspen CTP, winter school on black holes (1 week, winter 2015).

  • Cosmology on the Beach (COTB) (1 week in 2014).

  • Perimeter Institute (PITP), Waterloo, Canada, (2 weeks, August 2013).

  • Institute for the Early Universe (IEU), Seoul, Korea, (3 weeks, May 2013).

  • Lawrence Berkeley National Laboratory (LBNL), USA, (12 months - 2012).

  • UC Santa Cruz (UCSC), USA, (3 months in 2012-2013).

  • IPMU, Japan, (fall 2012).

  • Institute for Advanced Study (IAS), Princeton, PITP (summer 2011).

  • International Centre for Theoretical Physics (ICTP), Trieste, (summer 2010).

  • CERN, Switzerland, (3 months, 2009).

  • Lawrence Berkeley National Laboratory (LBNL), USA, (5 months. 2009).