TAPS 2020 projects

The main component of the summer program is an active participation in the selected Science research project offered by the staff members of the Nicolaus Copernicus University, please see the topics and their descriptions below. Interested students are welcome to contact possible advisors for more details concerning the foreseen projects and discuss the dates that the project could be undertaken.

IRX-M* relation out to redshift ~7

Most high-redshift galaxies lack infrared (IR) detections, tracing dust emission, due to the low resolution of single-dish IR telescopes or small field of view of IR interferometers. We, therefore, have to utilise indirect methods in order to account for the dust, which is crucial mainly for the correct estimates of the star formation rates (SFRs). One of the the main such methods involves determining the IR emission from the stellar mass of a given galaxy via the so-called IRX-M* relation. Problem is, it is not known whether this relation undergoes any redshift evolution. This project involves stacking 100k's of optically-selected galaxies in the far-IR Herschel/SPIRE and JCMT/SCUBA2 UDS maps in stellar mass bins, in order to investigate various dust properties of high-redshift galaxies and their evolution with redshift. The properties, depending on the efficiency of the student, will involve dust temperature, mass, IR luminosity, SFRs and, ultimately,IRX-M* relation. The student will gain experience in working with large data sets, stacking methods, deriving galaxy properties from fitting models to data and interpreting their results in order to understand galaxy evolution properties in the Universe. The basic knowledge of python will be an advantage, but is not a prerequisite.

Supervisor:	Maciej Koprowski (mkoprowski[at]fizyka.umk.pl)
Time:	01.07 – 28.07

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Optically thick globules in the solar vicinity

Interstellar medium (ISM) as an important component of the Milky Way system started to be considered in 1930 from the works of Trumpler who connected the observed optical thickness of interstellar clouds with the presence of dust particles. The interstellar absorptions are usually observed in spectra of young, massive, early type stars where stellar lines are scarce. Moreover, the above-mentioned stars are intrinsically bright which makes feasible their observations at long distances – probability of intersecting a cloud by a sightline grows with distance. However, very distant objects likely shine through several separate clouds which may be of different physical parameters (different spectra). This project is related to investigations of interstellar absorption lines or bands.
Bright and hot star (an object from the top of Main Sequence at the Hertzsprung-Russel diagram) is usually a „source of continuous spectrum”. Such objects are scarce in our Galaxy (Milky Way) but can be observed at very large distances. „Cloud of gas” is composed mostly of hydrogen and helium but about 1% of its mass is the dust. The latter causes the observed continuous extinction (colloquial: reddenening) of the observed star while the gas carries observed absorption lines and bands (the clouds contain a wealth of molecules). The massive stars are rapidly evolving objects and thus – young. One can expect in their spectra some effects of interstellar as well as circumstellar (relic) matter. Moreover, along very long sightline one can observe several absorbing clouds.
Our recent survey of Galactic reddened stars done with the aid of UVES spectrograph fed with the 8m Kueyen telescope (member of VLT) allows to select and investigate several late B type stars, likely obscured by single, geometrically small and likely homogeneous, interstellar clouds. These clouds are unlikely parts of the stellar parent clouds and thus their physical parameters may be deciphered. Thus such objects are very interesting and should be investigated as broadly as possible, so they will be a subject of study during this project.

Supervisor:	Jacek Krełowski (jacek[at]umk.pl)
	Andrzej Strobel (strobel[at]umk.pl)
Time:	06.07 – 31.07

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Mining of publicly available software repositories in context of replicable research

The researchers following the reproducible research movement tend to publish supporting resources like source code and data alongside the paper. Access to the source code supporting the research allows faster replication and validation of the results. Some new and interesting questions arise about these types of repositories, like structure, development cycle, and influence on future works and existing software. During this project Mining Software Repositories (MSR) techniques will be used to answer some of these questions. MSR concentrates on analysing rich data sources used in software development, like version control repositories, bug tracking tools, mailing lists and other, with the goal to uncover interesting and usable information that can help to improve software development. Good programming skills are required, but prior experience in MSR is not a must. We will provide tutorials on relevant topics at the beginning of the project.
The research tasks are as follows:

1. Identify source code repositories that hold supporting materials for research papers, on popular public access platforms, like github, bitbucket, but also publishers own solutions.
2. Identify type and field of the research.
3. Identify impact on other research projects.

Supervisor:	Piotr Przymus (eror[at]mat.umk.pl)
Time:	29.06 – 26.07 or 06.07 – 02.08

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Impact of scientific research contributions on software development

Scientific research has a large impact on software development. Some new methods and algorithms find their way into mainstream software projects. This poses new and interesting questions about the nature and dynamics behind scientific research and software development. During this project Mining Software Repositories (MSR) techniques will be used to answer some of them. MSR concentrates on analysing rich data sources used in software development, like version control repositories, bug tracking tools, mailing lists and other, with the goal to uncover interesting and usable information that can help to improve software development. One example of such scientific research and software development interaction can be the usage of the EWAH algorithm that found its place in Git software. Good programming skills are required (preferably in Python), but prior experience in MSR is not a must. We will provide tutorials on relevant topics at the beginning of the project.

The research tasks are as follows:

1. Identify source code repositories that take advantage of scientific research.
2. Identify type and field of the contribution.
3. Explore dynamics of this interaction.

Supervisor:	Piotr Przymus (eror[at]mat.umk.pl)
Co-supervisors:	Jakub Narębski (jnareb[at]mat.umk.pl)
Time:	29.06 – 26.07 or 06.07 – 02.08

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Synthesis of unbounded Petri nets

The project objective includes synthesis of concurrent systems in the form of unbounded Petri nets on the case of given specification (rational and semilinear seta, formal languages, infinite transition systems). The research tasks are as follows:

1. study on examples of known methods for the synthesis of unbounded Petri nets, basing on eight chapter of Badouel, Bernardinello, Darondeau: Petri Net Synthesis, Springer 2015 and bibliography of this chapter)
2. extending the list of potential base models and the development of new synthesis methods together with the designation of sufficient and necessary conditions
3. participation in Advanced Course on Petri Nets (6-12.09)

Supervisor:	Łukasz Mikulski (mikulskilukasz[at]gmail.com)
Time:	17.08 – 13.09

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Cold atoms optical frequency standards for science

Cold atomic experiments are composed of complex setups which require team work and broad knowledge for operation. During the four weeks internship student will be involved in current research activities connected with optical atomic clocks in CASTLE group (http://fizyka.umk.pl/~castle/). The main goal of the internship is to get experience in research team work. Optical atomic clocks with neutral cold atoms allows for absolute precision on the order of 10^-18, unmatched by any other device. They cover design of an active optical clock, construction of an ultra-stable laser for strontium atomic clock, and improvements of existing cold atom setups. Other activities are related to search of dark matter with atomic clocks and studies of fundamental physics with atom-light interaction.
The specific tasks including laser stabilization and optics, ultrastable cavities, vacuum setups, optical frequency combs, electronics and simulations can be adopted to student's interests and skills.

Supervisor:	Sławomir Bilicki (slawko[at]fizyka.umk.pl)
Co-supervisors:	Marcin Witkowski (marcin_w[at]fizyka.umk.pl)
Time:	01.06 – 31.07 (to be agreed)

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Spectroscopy with high-finesse cavities

The use of a high-finesse optical cavity extends the optical pathlength to several kilometers (the cavity is about 1 meter long) and allows precise measurements of weak absorption spectra. CRDS (cavity ring-down spectroscopy), CMWS (cavity mode width spectroscopy) and CMDS (cavity mode dispersion spectroscopy) are the spectroscopic techniques developed in our group allowing for precise measurements of the weak absorption spectra. The molecules spectra investigated in our laboratory are important for atmospheric studies, these include O₂, CO, CO₂. The TAPS student will get the opportunity to learn these experimental techniques working with the state-of-the-art spectrometer. Furthermore, student will be introduced to advanced spectral line shape models and multispectrum fitting technique.
Depending on the student’s interest and experience he/she may be involved in participation in ongoing measurements, data analysis, development and construction of a new spectrometer, development of the experimental control software.

Supervisor:	Jolanta Domysławska (jolka[at]fizyka.umk.pl)
Time:	29.06 - 24.07

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Methods of multilinear algebra in multipartite quantum entanglement detection and data analysis

Multilinear algebra deals with multi (more than 2) indices tensors, which entries can be arranged into multidimensional matrices. The student will get familiar with multidimensional generalisations of such notions as rank, deter- minant and singular value decomposition, which are more involved that their origin formulations for two-dimensional matrices. During the programme the student will learn the application of multidimensional matrices in problems of multipartite entanglement and data analysis.
During the stay the student will be introduced into problems of multilinear algebra, algebraic geometry, theory of entanglement and data analysis. The goal will be to solve a simple problem, like charactering a class of mul- tidimensional matrices of a given properties, classify types of entanglement within a given family of three-qubit states or something of similar level of difficulty.

Supervisor:	Gniewomir Sarbicki (gniewko[at]fizyka.umk.pl)
Co-supervisors:	Katarzyna Siudzińska (kasias[at]fizyka.umk.pl)
Time:	29.06 – 26.07

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Geometry of the Pauli channels

The goal of this project is to analyze the geometrical properties of a sub- set of quantum channels - Pauli channels. The Choi-Jamiołkowski isomor- phism between quantum states and quantum channels allows for equipping the manifold of states corresponding to the trace-preserving Pauli maps in the Hilbert-Schmidt metric. The associated volume element can be integra- ted analytically over the integration regions given in terms of the map’s eigenvalues. Relative volumes can be interpreted as the probability that a randomly generated Pauli map has the desired properties, like being comple- tely positive, entanglement breaking, divisible, or achievable with a legitimate time-local generator.
Research tasks include the derivation of the total volumes for important subclasses of the positive, trace-preserving Pauli maps. The calculations will be carried out for invertible maps with a full Kraus, non-invertible maps, and also dynamical maps, which provide the evolution for open quantum systems. The Pauli channels describe the mixed unitary evolution of a qu- bit. They found many applications in quantum information theory, quantum information processing, quantum communication, and many more.

Supervisor:	Gniewomir Sarbicki (gniewko[at]fizyka.umk.pl)
Co-supervisors:	Katarzyna Siudzińska (kasias[at]fizyka.umk.pl)
Time:	03.08 –30.08

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