The Disastrous Situation Experiments over the last year have - - PowerPoint PPT Presentation

The Disastrous Situation…

Experiments over the last year have verified

• ur standard model, and confirmed the earlier

indirect indications of no new physics to better than 5 sigma

The Disastrous Situation…

just terrible…!

…or, what gravity wave detectors can tell us about BSM physics

John March-Russell Oxford University

Isabel Garcia Garcia, Sven Krippendorf, JMR — arXiv:1607.06813

The String Soundscape

Gravitational Waves

• GW have been directly observed by LIGO,

and many new detectors will be built

• The astrophysical potential

• f GW detectors has been


extensively studied


• Can we use GW experiments to learn about

BSM? BlackHoles Neutronstars pulsars supernovae

e.g. see Lasky et al. arXiv:1511.05994

GW detectors for BSM

There are a few examples:

• Inflation
• Strong 1st order EW (& QCD) phase

transitions


• Probing the existence of a QCD axion


due to BH super-radiance perfectforeLISA (iftheyexisted!) withaLIGO

Review: Caprini et al. arXiv:1512.06239 Arvanitaki et al. arXiv: 1411.2263 & 1604.03958

GW detectors for BSM

There are a few examples:

• Inflation
• Strong 1st order EW (& QCD) phase

transitions


• Probing the existence of a QCD axion


due to BH super-radiance perfectforeLISA (iftheyexisted!) withaLIGO

Review: Caprini et al. arXiv:1512.06239 Arvanitaki et al. arXiv: 1411.2263 & 1604.03958

+GWsignalsfromvacuumdecayin StringTheorymotivatedscenarios

Since here in Trieste the seafood is so good I'm sure that you'll vividly be able to picture the type-IIB string flux compactification landscape

D3 H3 F3

warped

Standard Model

unwarped

D3

D-branes for moduli stabilisation KS throat

the string polyfaucibus

A typical stringy set-up: alotofhighlywarped regions:throats (thinkRS!) SM??? manyhidden sectors!

String Flux Compactifications

(the6compactified dimensions)

String Flux Compactifications

Throats are due to back-reaction from fluxes (need many pairs of integer fluxes K, M for the landscape)

warpfactoratthroat tip

String Flux Compactifications

alotofthesethroatshave anti-D3branes(itisasevere restrictionotherwise)

String Flux Compactifications

thesepanti-D3'sleadtoeithera classicallyunstableconfiguration

• rametastableone

A typical throat features a metastable, SUSY-breaking, false vacuum, as well as a true (locally) SUSY-preserving one

ψ Veff(ψ) π ψfv

truevacuum false vacuum

ρvac

String Flux Compactifications

Kachru, Pearson, Verlinde: hep-th/0112197

physicsdescribedbyeffective angularscalarfield

ψ Veff(ψ) π ψfv

truevacuum false vacuum

ρvac

String Flux Compactifications

leadingeffective Lagrangian

String Flux Compactifications

non-standardDBI-likekineticterms(makesadifference tocriticalbubbleprofile,andlaterevolution) (hereI'vesetMstr=1andamworkinginred-shiftedunitssotip warpfactorwIRishidden)

String Flux Compactifications

asratiop/M=rreachesacriticalvalue barrierdisappears,sodefine

ψ Veff(ψ) π ψfv

truevacuum false vacuum GWfrom vacuumdecay

ρvac

String Flux Compactifications

asfalsevacuumdecaybecomesfast

δ → 0

For this talk some simplifying assumptions:

• After inflation, throat in its metastable vacuum
• Visible sector reheated at but

hidden throat sector left at 


• Universe radiation dominated throughout

Trh & 4 MeV Tth ≈ 0

sodecayoccursviaquantumtunnelling (mayberelaxedtoincludeaphaseofmatterdomination)

ρtotal(T) = ρrad(T) + ρvac with α(T) ≡ ρvac ρrad(T) ≤ 1

String Flux Compactifications

Bubblesform expand collide! TheUniverse isina newphase … …

Bubblesofthetruevacuumare nucleatedintheearlyUniverse Theyquicklystart expandingatthe speedoflight Bubblescollide,emitting gravitywaves(andmaybe formingsomepBHstoo…)

Vacuum decay

Vacuum decay

T ∼ 1 MeV

Nucleation probability increases as Tvis falls

∼ Γ H(T)4

decayrateperunit volume(Tindependent) decreasesasthe
 temperaturedrops

when the transition starts

Γ H(Tn)4 ≈ 1

Tn

false vacuum! true vacuum!

Tvis

Vacuum decay

Nucleation probability given by Coleman's bounce solution We find for our system always a thick-walled bounce

Vacuum decay

Nucleation probability given by Coleman's bounce solution We find for our system always a thick-walled bounce

Gravity Wave Spectrum

Putting everything together we find a stochastic gravity wave spectrum with approximate peak frequency

visibletemperature atbubblecollision durationoftransition inHubbletimes

Gravity Wave Spectrum

Putting everything together we find a stochastic gravity wave spectrum with approximate peak frequency

visibletemperature atbubblecollision durationoftransition inHubbletimes

nucleationtemperatureTnisexponentiallysensitiveto underlyingthroatparameterssof0scans

GW peak frequency

f0 Hz Tc GeV wIR

V=102 V=1010 V=1018 10-15 10-12 10-9 10-6 10-3 10-11 10-8 10-5 10-2 10 104 107 10-4 10-1 102 105 108 1011 1014 d=10-3 d=10-2

(herehavefixedM=102andgs=0.03)

GW peak frequency

f0 Hz Tc GeV wIR

V=102 V=1010 V=1018 10-15 10-12 10-9 10-6 10-3 10-11 10-8 10-5 10-2 10 104 107 10-4 10-1 102 105 108 1011 1014 d=10-3 d=10-2

warpfactoratthe tipofthethroat

GW peak frequency

f0 Hz Tc GeV wIR

V=102 V=1010 V=1018 10-15 10-12 10-9 10-6 10-3 10-11 10-8 10-5 10-2 10 104 107 10-4 10-1 102 105 108 1011 1014 d=10-3 d=10-2

decreasing

δ

GW peak frequency

f0 Hz Tc GeV wIR

V=102 V=1010 V=1018 10-15 10-12 10-9 10-6 10-3 10-11 10-8 10-5 10-2 10 104 107 10-4 10-1 102 105 108 1011 1014 d=10-3 d=10-2

volumeofcompactification increasing

GW peak frequency

f0 Hz Tc GeV wIR

V=102 V=1010 V=1018 10-15 10-12 10-9 10-6 10-3 10-11 10-8 10-5 10-2 10 104 107 10-4 10-1 102 105 108 1011 1014 d=10-3 d=10-2

Thefrequencycanspantheentirerangebeing/to-beprobed bygravity-wavedetectors

GW peak frequency

f0 Hz Tc GeV wIR

V=102 V=1010 V=1018 10-15 10-12 10-9 10-6 10-3 10-11 10-8 10-5 10-2 10 104 107 10-4 10-1 102 105 108 1011 1014 d=10-3 d=10-2

requiresthatatleastoneofthemanythroatsinatypical fluxcompactificationhasinsuitablerange

δ

GW peak frequency

f0 Hz Tc GeV wIR

V=102 V=1010 V=1018 10-15 10-12 10-9 10-6 10-3 10-11 10-8 10-5 10-2 10 104 107 10-4 10-1 102 105 108 1011 1014 d=10-3 d=10-2

requiresthatatleastoneofthemanythroatsinatypical fluxcompactificationhasinsuitablerange

δ

notguaranteedofcourse butnotunreasonableeither

GW signal strength

Signalstrengthislargedueto:

• longdurationoftransition(nucleationratedoesnot

increasewithfallingTunlikethermalcase)

• ultra-relativisticexpansionofbubbles(nothermal

plasmatoimpedeexpansion)

f0 / Hz ΩGW h2

10-10 10-7 10-4 10-1 102 105 10-15 10-12 10-9 10-6 10-3 EPTA SKA aLIGO BBO eLISA LISA ac=10-1 ac=10-2 ac=10-3

αc ≡ ρvac ρrad(Tc)

GW signal strength

falsevacuumenergy decreasing

f0 / Hz ΩGW h2

10-10 10-7 10-4 10-1 102 105 10-15 10-12 10-9 10-6 10-3 EPTA SKA aLIGO BBO eLISA LISA ac=10-1 ac=10-2 ac=10-3

GW signal strength

NOTtheactualhigh- frequencybehaviourof spectrum-justthe usualoneforguidance

f0 / Hz ΩGW h2

10-10 10-7 10-4 10-1 102 105 10-15 10-12 10-9 10-6 10-3 EPTA SKA aLIGO BBO eLISA LISA ac=10-1 ac=10-2 ac=10-3

GW signal strength

Differentbecause

• hasunusualT-dep
• Bubblesarethick-wall
• DBIkinetic-termleads

tonewfeatures

Γ/H4

(workinprogress)

f0 / Hz ΩGW h2

10-10 10-7 10-4 10-1 102 105 10-15 10-12 10-9 10-6 10-3 EPTA SKA aLIGO BBO eLISA LISA ac=10-1 ac=10-2 ac=10-3

GW signal strength

high-frequency partofspectrum sensitiveto underlying (string)model!

Black hole production?

Themostinteresting"high-frequency"issueisthepossible formationofprimordialblackholes Anoldstory,butinfact,veryincompleteandpoorlyunderstood

basicallycorrect,butnotexactly… crucialissueistheSO(3,1)symmetryofasinglebubble,andthe associatedO(2,1)symmetryoftwocollidingbubbles

…ah the days when one could have a cigarette after (or during) a stimulating seminar but some knew otherwise

Return of the bounce

UsuallystatedthattheEuclidianbouncesolutionwithO(4)symmetry impliestheinitialconfigurationofthenucleatedcriticalbubbleis highlysymmetric

Return of the bounce

ButSidneytaughtmethatasinglefieldconfigurationcontributes measurezerototheeuclidianfunctionalintegral UsuallystatedthattheEuclidianbouncesolutionwithO(4)symmetry impliestheinitialconfigurationofthenucleatedcriticalbubbleis highlysymmetric

Return of the bounce

ButSidneytaughtmethatasinglefieldconfigurationcontributes measurezerototheeuclidianfunctionalintegral UsuallystatedthattheEuclidianbouncesolutionwithO(4)symmetry impliestheinitialconfigurationofthenucleatedcriticalbubbleis highlysymmetric Reallytogetanon-zerodecayrateofform

• neneedstoconsiderabundleofnearbyconfigurations

Return of the bounce

UsuallystatedthattheEuclidianbouncesolutionwithO(4)symmetry impliestheinitialconfigurationofthenucleatedcriticalbubbleis highlysymmetric Infacttypicalconfigurationatnucleation typicalrelative velocitiesofparts

• fwall~1/

√ B typicalnon-sphericity ~1/ √ B

Return of the bounce

UsuallystatedthattheEuclidianbouncesolutionwithO(4)symmetry impliestheinitialconfigurationofthenucleatedcriticalbubbleis highlysymmetric Infacttypicalconfigurationatnucleation typicalrelative velocitiesofparts

• fwall~1/

√ B typicalnon-sphericity ~1/ √ B thissymmetrybreakingcansurvivebubbleexpansionandpossiblydominantly determinespBHformationrateandformofmassdistribution! (workinprogress-reallyneedsdedicatedstrong-field-gravitynumerics!)

• GW detectors will help shape the future of physics in the

coming century

• They can complement the information we get from particle

colliders/DM detection experiments/ultra-sensitive small scale experiments

• String theory transitions in post-inflation early universe can be

present and lead to (distinctive) GW signatures, and maybe even an interesting population of pBHs!

Conclusions

moretocome….

I now think I need that cigarette…