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SES4U Thomas Smith 28/09/2014 Primordial Waves and Flatness: An Analysis of the Planck Satellite General Description and Scientific Goals: The Planck Satellite is a space observatory orbiting at the L2 Lagrange Point (1,500,00 km) designed to answer key cosmological questions including: observation and analysis of anisotropies in the CMB( Cosmic Microwave Background); specifically intensity and polarization which has recently [4] had disheartening effects on the possibility of gravitational waves form BICEP2; these results were part of the second main goal of the project; that of analyzing infrared and radio frequency sources (Collaboration, Planck, 2009). For motivation a direct quotation from the Collaboration is most apt: CMB measurements with high angular resolution and sensitivity are required to determine the initial conditions for structure evolution, the origin of primordial uctuations, the existence of topological defects, and the nature and amount of dark matter. (Collaboration, Planck, 2009). Development history is also most succinctly phrased in the report as: ESA released an Announcement of Opportunity for Planck instruments in October 1997.Two proposals were received: the Low Frequency Instrument (LFI, an array of receivers based on HEMT ampliers, covering the frequency range 30100 GHz, and operated at a temperature of 20 K), led by N. Mandolesi (INAF, Bologna); and the High Frequency Instrument (HFI, an array of receivers based on bolometers covering the frequency range 100857 GHz, and operated at a temperature of 0.1 K), led by J. L. Puget (IAS, Orsay). After detailed review by independent scientists, both proposals were accepted by ESA in February 1999. The telescope mirrors will be provided by ESA and a Consortium of Danish institutes (referred to as DK-Planck) led by H. U. Norgaard-Nielsen (DSRI, Copenhagen) (Collaboration, Planck, 2009). Canada plays a specific role in the LFI as outlined in [1] as: Members of the Canadian LFI team have been involved with the planning of the Planck science program. They are active members of the Planck core team, whose task is to deliver the final data to the Planck consortium and wider scientific community. Work they have been involved in, for example, includes an effort to understand the recombination history of the universe to high precision and modelling systematics in the CMB polarization maps which Planck will produce. Canadian team members, led byRuss Taylor, are also involved in the Planck DRAO Deep Fields project, which consists of high resolution observations of the polarized astrophysical foregrounds at high galactic latitude. Since a key science goal of Planck is to measure the CMB polarization at high precision, it is necessary to have a good understanding of polarized foregrounds for which this project will be important (Canadian LFI Team, 2014). Applications of Planck to Areas of Fundamental Research: Due to space constraints this section will consist of condensed text from the Planck report and brief comments from the publicly available paper only applicable to a single area of research: inflationary cosmology and gravitational waves. Planck and Inflation: The report offers a clear motivation for inflationary ideas as follows: The origin of the uctuations that grew to make clusters, galaxies and all of the other structure in our Universe poses a fundamental problem/ It is easy to see why exotic physics needs to be invoked: a map of the CMB temperature anisotropies provides a snapshot of the uctuations at the time of recombination, when the Universe was only tr 400,000 years old. However, the distance that light could have travelled within this timescale, L ctr, would subtend an angle of only about a degree on the sky/the uctuations could not, according to this naive argument, have been in causal contact at the time of recombination (Collaboration, Planck, 2009). The argument then follows that, following the Freidman equation, a state of matter with negative pressure would result in an exponential expansion of space-time accounting for the flatness of space. Planck could make contact with this area of physics through the following: A detection of a large-angle signal with a thermal spectrum would provide a smoking-gun signature of a stochastic background of gravitational waves. In models of ination, the amplitude of the B-mode of polarization is a direct measure of the inationary energy scale, and so detection would provide a rm observational link with physics of the early Universe (Collaboration, Planck, 2009). They provide a clear description of a decomposition of the polarization map into E and B modes as spherical harmonics, the latter of which being a direct prediction of inflationary theory. This has led to the disheartening effect of ruining the BICEP2 data by showing a very strong correlation between predictions from a dust model and B-modes versus that of gravitational waves as shown in the following graphs: Figure 1: B-Mode Polarization as a function of Radius with BICEP2 data outlined

Figure 2: Correlation of B-modes as a function of Multipole Moment

To see why this damaging requires a little explanation: The light-blue rectangles are what Planck actually sees and attributes to dust. The black line is the theoretical prediction for what you would see from gravitational waves with the amplitude claimed by BICEP2. As is clear, they match very well. That is: the BICEP2 signal is apparently well-explained by dust. Multipole moments are the coefficients in a spherical harmonic expansion of an inverse radi varying potential (see Classical Electrodynamics by Julian Schwinger). Correlation functions are exactly what their name implies: a measure of the relation of an output to input parameters. A final test of BICEP2 is given in [4] as: Figure 3: Relative Power of Signal vs Frequency With the black dotted line being the prediction due to dust (Planck Collaboration, 2014). Clearly, the Planck satellite has an interesting and fascinating ability to shed light on our most fundamental questions in science and, finally, offer constraints on the plethora of ideas coming out of theoretical physics, its relation to better lives on Earth mostly being given by its impacts on theoretical ideas at the cutting edge of physics which may create giant benefits e.g. its possible constraints on string theory models and the paper [3] through possibly making Ads/CFT intractable. BibliographyAll figures taken from [4]Canadian LFI Team, 2014. Canadian LFI Team. [Online] Available at: http://www.astro.ubc.ca/Planck/index.html[Accessed 28 09 2014]. [1]Collaboration, Planck, 2009. Planck: The Scientific Programme, s.l.: European Science Agency. [2]Jeffrey Wouda, 2012. Holographic Superconductors, s.l.: University of Amsterdam. [3]Planck Collaboration, 2014. Planck intermediate results. XXX. The angular power spectrum of polarized dust emission at intermediate and high Galactic latitudes, s.l.: ArXiv, [4]