1 / 7

Generating hierarchy and inflation in supergravity

Generating hierarchy and inflation in supergravity. Tirthabir Biswas IGC, Penn-State University With A. Notari, hep-ph/0511207 With A. Notari, S. Alexander & N. Okada in prep. The Hierarchy Problem. Fundamental scales are widely seperated Why is gravity so much weaker than Electro-weak?

leal
Télécharger la présentation

Generating hierarchy and inflation in supergravity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Generating hierarchy and inflation in supergravity Tirthabir Biswas IGC, Penn-State University With A. Notari, hep-ph/0511207 With A. Notari, S. Alexander & N. Okada in prep.

  2. The Hierarchy Problem Fundamental scales are widely seperated Why is gravity so much weaker than Electro-weak? Related (?) hierarchies: • Little hierarchy problem: • Hierarchy in quark masses: few MeV to Tev Attempts at solving the Hierarchy problem: • SUSY: if broken at ~ Tev can protect the hierarchy • Extra dimensions: Single fundamental mass scale (Mew) Mpl is derived, depends on extra-dimensions. Ratio can be made small by having them warped [RS] or large [ADD]

  3. Old Inflation (Guth) Slow-roll Inflation very successful, but • Concrete realization in ST or PP have been difficult • Typical scenarios involve fine tuning issues Inflation from false vacuum energy Why can’t it work? • If tunneling rate , the Hubble rate not enough inflation • If , never-ending inflation

  4. “Graceful” Old Inflation f(Φ) has a minimum, e.g. • Non-minimal coupling implies Φ & effective Mpl evolves during inflation from false vacuum • Even if initially Hubble rate decreases as Planck scale increases Inflation ends when • At this point bubbles nucleate and collide and reheats the universe • Einstein frame: hill top inflation with & reproduces observed tilt & amplitude

  5. Generating Hierarchy • When exponential inflation ends, & f(Φ) ~ O(1) • Universe expands as power law still driven by false energy as long as f(Φ) > Φ2 f(Φ) starts to grow • Finally the universe tunnels from the false vacuum having generated

  6. Future Research Signatures • Fundamental scale ~ Tev, new physics at LHC • Reheat temperature ~ Tev, gravity waves detectable at LISA. Accurate calculation required. Missing • Concrete PP or ST (supergravity) set-up • Requires a small hierarchy • A small “unprotected” parameter β • Quasi-periodic potential to stabilize Φ after tunneling to avoid 5th force constraints • Why SM doesn’t couple to Φ?

  7. Supergravity Embedding Advantages • Non-minimal coupling: Naturally given by Kahler potential But, it also determines kinetic piece. What works? & • Hierarchy: power law phase inflating • False vacuum: In SQCD such non-susy vacuum exists[Intrilligator et. al] Moreover, & one can have[Dine et. al] One can have long lived metastable vacua • Periodic potential: A coupling of Φ to the SQCD sector generates an F F† term which generates a periodic potential for Φ via chiral condensation of fermions.

More Related