Marek Walczak

If binaries consisting of two ∼100 M☉ black holes exist, they would serve as extraordinarily powerful gravitational-wave sources, detectable to redshifts of z ∼ 2 with the advanced LIGO/Virgo ground-based detectors. Large uncertainties about the evolution of massive stars preclude definitive rate predictions for mergers of these massive black holes. We show that rates as high as hundreds of detections per year, or as low as no detections whatsoever, are both possible. It was thought that the only way to produce these massive binaries was via dynamical interactions in dense stellar systems. This view has been challenged by the recent discovery of several ≳ 150 M☉ stars in the R136 region of the Large Magellanic Cloud. Current models predict that when stars of this mass leave the main sequence, their expansion is insufficient to allow common envelope evolution to efficiently reduce the orbital separation. The resulting black hole–black hole binary remains too wide to be able to coalesce within a Hubble time. If this assessment is correct, isolated very massive binaries do not evolve to be gravitational-wave sources. However, other formation channels exist. For example, the high multiplicity of massive stars, and their common formation in relatively dense stellar associations, opens up dynamical channels for massive black hole mergers (e.g., via Kozai cycles or repeated binary-single interactions). We identify key physical factors that shape the population of very massive black hole–black hole binaries. Advanced gravitational-wave detectors will provide important constraints on the formation and evolution of very massive stars.

The nature of dark matter remains unknown and its origin is currently one of the most important questions in physics.In particular direct searches for WIMP dark matter particle interactions with ordinary matter are carried out with large detectors located in underground laboratories to suppress the background of cosmic rays.One of the currently most promising detection technologies is based on the use of a large mass of liquid argon or xenon as a target in the detector.This article discusses dark matter searches with detectors based on liquid argon, in particular DarkSide-20k experiment, which is under construction at the Gran Sasso laboratory, Italy.

Dialog Table is a shared interface where you use hand gestures to discover a museum's collection. Several people can gather around and together explore the table's movies, narratives and 3D journeys. The table provides an opportunity for people to discuss with each other their thoughts on what they have seen. Several teen beta-testers said they wanted their desk at home to work just like the table. The table can work in situations as varied as hospital kiosks, conference rooms, collaborative design stations, game rooms, bedrooms...Dialog Table was commissioned by the Walker Art Center through an international design competition to promote social interactions among visitors, to provide access to the Walker's multidisciplinary collections, and to facilitate learning about art. The table was designed by Marek Walczak, an artist and architect, Michael McAllister, an industrial designer and Jakub Segen, a leader in recognition systems. http://dialogtable.com.

The most recent results of Standard Model physics using 13 TeV protonproton collisions data recorded by CMS detector during the LHC Run 2 are reviewed.This overview includes studies of several results of Forward and Small-x QCD physics, B physics and Quarkonia, Standard Model physics and Top physics.The outlined results are compared to the corresponding theoretical predictions and no significant deviation is observed.

We calculate the production of a photon and two jets at forward rapidity in proton-nucleus collisions within the hybrid dilute-dense framework in the Color Glass Condensate (CGC) formalism.After obtaining the cross section for the quark-initiated channel, we consider the correlation limit, in which the vector sum of the transverse momenta of the three outgoing particles is small with respect to the individual transverse momenta.In this limit, the cross section simplifies considerably and can be written in a factorized form, sensitive to various unpolarized and linearly-polarized transverse-momentum-dependent gluon distribution functions (gluon TMDs).