Understanding Primordial B-modes and Cosmic Inflation

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In summary, this rumor over the detection of primordial B-modes has got me thinking. Gravitational waves are caused by perturbations in spacetime by asymmetrical objects. So for them to travel, they have to be propagated by something: spacetime. The primordial B-modes are supposedly the result of cosmic inflation. So two things don't make sense to me. Wouldn't spacetime had to have existed pre-Big Bang as to have B-modes produced from the inflation? Assuming spacetime is a result of the Big Bang, inflation would have been the expansion of spacetime itself, meaning no gravitational waves could be generated by inflation as they couldn't be propagated in the same spatial and temporal dimensions
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connorp
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So this rumor over the detection of primordial B-modes has got me thinking. Gravitational waves are caused by perturbances in spacetime by asymmetrical objects. So for them to travel, they have to be propagated by something: spacetime. The primordial B-modes are supposedly the result of cosmic inflation. So two things don't make sense to me. Wouldn't spacetime had to have existed pre-Big Bang as to have B-modes produced from the inflation? Assuming spacetime is a result of the Big Bang, inflation would have been the expansion of spacetime itself, meaning no gravitational waves could be generated by inflation as they couldn't be propagated in the same spatial and temporal dimensions as their medium.

Also, since "objects" must be asymmetrical to create gravitational waves, how could cosmic inflation produce them, since inflation is considered to be isotropic, and therefore, in a sense, symmetrical?

I know the majority of what I'm asking is purely theoretical, but please explain as best as possible. And feel free to correct me anywhere, as I am no where near being a cosmological expert. Thanks.
 
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This Sky and Telescope article seems fairly basic and might get you started until the experts get out of bed.

http://www.skyandtelescope.com/news/Proof-of-Inflationary-Universe-To-Be-Announced-Monday-250522521.html
 
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Spinnor said:
This Sky and Telescope article seems fairly basic and might get you started until the experts get out of bed.

http://www.skyandtelescope.com/news/Proof-of-Inflationary-Universe-To-Be-Announced-Monday-250522521.html

Nice article and a witty comment. And thanks! my subscription for their newsletter was confirmed just now :-)
 
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Spinnor said:
Some more basic reading,

http://www.washingtonpost.com/natio...c21850-adfc-11e3-9627-c65021d6d572_story.html

http://www.newscientist.com/article...ipples-from-universes-birth.html#.Uye2gKhdWSo

http://background.uchicago.edu/~whu/polar/webversion/node8.html

http://background.uchicago.edu/~whu/polar/webversion/node9.html

http://cosmology.berkeley.edu/~yuki/CMBpol/CMBpol.htm

http://astrobites.org/2013/07/24/lensing-b-modes-in-the-cosmic-microwave-background-polarization/

Those are excellent reading materials especially those with .edu in the url, besides that I'm also reading what matt strassler and sean carroll are telling about that.
http://profmattstrassler.com/2014/03/18/if-its-holds-up-what-might-bicep2s-discovery-mean/
http://www.preposterousuniverse.com...nal-waves-in-the-cosmic-microwave-background/
 

1. What is cosmic inflation?

Cosmic inflation is a theoretical concept in the field of cosmology that suggests the universe underwent a rapid and exponential expansion in the first fraction of a second after the Big Bang. This rapid expansion is believed to have smoothed out the initial irregularities in the universe and laid the foundation for the structure we see today.

2. What are B-modes?

B-modes, or primordial B-modes, are a type of polarization pattern in the cosmic microwave background (CMB) radiation. These patterns can provide evidence of gravitational waves produced during cosmic inflation.

3. How are B-modes detected?

B-modes are detected by studying the polarization of the CMB radiation using specialized telescopes and instruments. The polarization of the CMB is measured by looking at the orientation of the electric field of the radiation, which can be affected by gravitational waves.

4. Why is understanding B-modes and cosmic inflation important?

Understanding B-modes and cosmic inflation can provide valuable insights into the early universe and help us better understand the fundamental laws of physics. It can also help us test and refine our theories about the formation and evolution of the universe.

5. What are the current challenges in studying B-modes and cosmic inflation?

One of the main challenges in studying B-modes and cosmic inflation is the detection of these weak signals from the CMB. This requires highly sensitive instruments and careful analysis of data. Another challenge is distinguishing between B-modes produced by gravitational waves and those caused by other sources, such as dust in our own galaxy.

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