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Research topics - different intensities at Licencjat/Magister/Doktorat level

CMB/WMAP/Planck - the Missing Fluctuations problem

mag/lic, astronomia/fizyka matematyczna

WMAP data, without correction for the spacecraft attitude timing-offset-induced calibration error (Liu & Li ArXiv:1003.1073, Roukema ArXiv:1007.5307), are too homogeneous on the largest scales to match the infinite flat model, e.g. see Copi et al. 2009 ArXiv:0808.3767. The calibration error implies that about half the "CMB" quadrupole signal is an artefact, worsening the disagreement of the infinite flat model with the data in the spherical harmonic approach. Summarise the evidence; discuss the correlation function versus spherical harmonic interpretations of the data; list possible explanations, including the topology of the Universe as discussed by Karl Schwarzschild, Leopold Infeld, et al.

http://cosmo.torun.pl/Cosmo/LicMagTematy

Topology of the Universe

mag/lic, astronomia/fizyka matematyczna

If you are interested in cosmic topology and have good software skills and/or a good understanding of differential geometry, many interesting observational and theoretical projects are available upon consultation - start reading at MonographCosmo.

http://cosmo.torun.pl/Cosmo/LicMagTematy

Clusters, Lambda, and OCRA/SZ Effect

mag/lic, astronomia/fizyka matematyczna

The largest gravitationally collapsed (virialised) objects in the Universe are clusters of galaxies. In principle, these should be easy to use as cosmological tracer objects in various ways. The simplest interpretation of clusters observed by XMM-Newton using the apparent gas fraction at the virial radius appeared to support a high-density (e.g. zero cosmological constant) model - Sadat et al. 2005 AstroPh:0503426, in contradiction to the Concordance Model. Resolving this contradiction may lead to new understanding of the dynamics and outer parts of clusters, e.g. Kay et al. 2007 AstroPh:0611017, Ferramacho, Blanchard 2007 AstroPh:0609822. Estimate what role RT4/OCRA-f and RTK could play in testing our understanding of clusters.

http://cosmo.torun.pl/Cosmo/LicMagTematy

Dark Energy as a good phenomenological fit

mag/lic, astronomia/fizyka matematyczna

Summarise the evidence (it did not start with the SNe Ia project); list different types of explanations; give arguments for and against the different candidates; investigate the evidence numerically and produce your own plots. See ArXiv:0903.0866 and ArXiv:0904.0975 and references therein. Two more recent reviews: ArXiv:1103.2016 Buchert ArXiv:1102.1449 Bolejko, Celerier, Krasiński.

http://cosmo.torun.pl/Cosmo/LicMagTematy

The averaging problem

mag/lic, astronomia/fizyka matematyczna

The Universe is not homogeneous, but the Concordance Model starts with a spatially-homogeneous solution to the Einstein field equations and only afterwards applies perturbations. How significant are the errors introduced by this approximation? See e.g. Carfora and Buchert ArXiv:0803.1401, Wiltshire ArXiv:0912.5234, Krasinski et al ArXiv:0903.4070. Check at least one of these calculations at the level appropriate for your level of studies.

http://cosmo.torun.pl/Cosmo/LicMagTematy

Dark Matter (DM)

mag/lic, astronomia/fizyka matematyczna

Summarise the evidence; list different types of explanations; give arguments for and against the different candidates; investigate the evidence numerically and produce your own plots. In particular,
  • the Light Dark Matter hypothesis AstroPh:0507142 seems very interesting (is the 511 keV line emission in the galactic centre due to annihilating LDM?); and
  • the DAMA/NaI and DAMA/LIBRA results are interesting - see Bernabei et al. (2008), ArXiv:0804.2741 "the presence of Dark Matter particles in the galactic halo is supported, on the basis of the DM annual modulation signature, at 8.2 σ C.L." and Savage et al. (2009), ArXiv:0808.3607 and references therein;
  • the CDMS (Cryogenic Dark Matter Search) initial results look exciting.
  • could DM be an artefact induced by not applying general relativity correctly? see Buchert & Wiegand ArXiv:1002.3912
  • Warning: microlensing (OGLE etc.) so far only gives evidence of that DM is (mostly) not composed of stellar-mass MACHOs e.g. AstroPh:0607207.

http://cosmo.torun.pl/Cosmo/LicMagTematy

już ktoś robi...

Topology of the Universe Detection

  • In http://de.arxiv.org/abs/0801.0006, it seems that we may have measured the shape of the Universe, since certain parts of the cosmic microwave background seen by the WMAP satellite appear to be seen twice in different directions on the sky, due to topological lensing. The purpose of the masters/licencjat project is:
  • Aim: Propose and apply a further test using WMAP data which further tests the hypothesis. This requires:
    • Reading/writing/managing the WMAP data file with free software computer programs
    • Statistical analysis
    • Independently checking that the computer code does the algebraic and statistical analyses correctly

źródło: LambdaStudentTematAbstrakt

Czy ,,stała kosmologiczna" jest tylko efekt uśrednienia niejednorodności?

Is the cosmological constant just the result of inhomogeneities?

See e.g. Buchert et al. GrQc:0210037, GrQc:0210045, AstroPh:9609036

źródło: LDMStudentTematAbstrakt

Dark Matter - Light Dark Matter (LDM) hypothesis - Galaxy Centre INTEGRAL results

Stary

"Stary" does not necessarily mean the topic is no longer open. It only means that I (Boud) do not see it as a good student topic that I am interested in supervising right now.

Cosmic String Detection

źródło: DAMAStudentTematAbstrakt

Dark Matter Detection - DAMA/NaI + Foot et al.

  • In http://de.arxiv.org/abs/astro-ph/0405282 the 7 year results of the DAMA/NaI dark matter direct detection experiment show a signal significant at 6.3σ according to the authors. An explanation for why a signal from mirror-baryonic matter should be expected in this experiment but not in others with similar cross-section detection parameters is presented in AstroPh:0403043, see also AstroPh:0407623 and references therein.
  • Aim: Check the experimental and theoretical claims and propose further tests
    • Try to find an alternative explanation for the DAMA/NaI results without going beyond the Standard Model of particle physics
    • Check whether the Foot et al. calculations of mirror matter properties are consistent with all the experimental data as the authors claim
    • Extend the Foot et al. calculations to find, e.g. a non-gravitational effect of mirror matter in stellar physics, e.g. symbiotic stars (gravitational effects of dark matter are already well studied)
  • More info: http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/NonBaryonicDarkMatter#the_DAMA_NaI_detection_and_mirro
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Topic revision: r18 - 22 Dec 2011, BoudRoukema
 
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