Experimental search for Planck Stars Francesca Vidotto with - - PowerPoint PPT Presentation

Experimental search for Planck Stars

Francesca Vidotto

with A.Barrau, H. Haggard, C. Rovelli

SISSA, Trieste - September 3rd, 2014 Experimental Search for Quantum Gravity

!

Singularity resolution

canonical

SU(2) group variables Minimal area gap Hamiltonian constraint Holonomy corrections

• 1.2
• 1
• 0.8
• 0.6
• 0.4
• 0.2

|!(v,")| v " |!(v,")|

˙ a2 a2 = 8πG 3 ρ ✓ 1 − ρ ρc ◆

Heff = − 3 8πG sin(λγ ˙

a a)

λγ !2 a3 + Hmatt

motion of an accelerated observer in spacetime evolution of spacetime seen by an observer

{ Loop Quantum Gravity is a theory about spacetime quanta:

No need to violate SEC !

covariant

SU(2) group variables Minimal area gap Simplicity constraint Maximal acceleration

P 0 P z

t

Rovelli,Vidotto 1307.3228 Boost generator Rotation generator

~ K + ~ L = 0

= 1/a

W(η, j) = hj, j|Y †eiηKzY |j, ji

Big Bounce

What have we learnt from Loop Quantum Cosmology?

Ashtekar,Pawlowski, Singh, Vandersloot 0612104!

!

see talks by Grain and Martin-Benito!

• 1.2
• 1
• 0.8
• 0.6
• 0.4
• 0.2

1*104 2*104 3*104 4*104 5*104 v φ quantum classical

v expanding
 solution contracting
 solution

Quantum Tunneling Effective repulsive force Size Planck length

superposition Planck density

• V

Vb ∼ m mP `3

P ≈ 1024cm3

See also related works by Bianchi, Smerlak, Perez, Gosh, Frodden, Gambini, Pullin…

• Where does matter falling into a Black Hole go?

See works by Barrau, De Lorenzo, Haggard, Pacillo, Rovelli, Speziale, Vidotto…

Planck Stars

Quantum Tunneling Effective repulsive force Size Planck length

superposition Planck density

rb ∼ m mP `P

Rovelli, Vidotto 1401.6562!

!

see talk by Rovelli

r = 2m r = rin

horizon

r t r = 0

Effective theory

Vidotto, Rovelli 1401.6562 


! ! ! ! ! ! ! ! !

Hayward 0506126
 Koch, Saueressig 1401.4452

ds2 = r2dω2 + 2dv dr − F(r)du2

F(r) = 1 − 2mr2 r3 + 2α2m

F(r) = (1 − 2m/r)

Eddington-Finkelstein coordinates

r = 2m r = rin

horizon

r t r = 0

Effective theory

Vidotto, Rovelli 1401.6562 


! ! ! ! ! ! ! ! !

Hayward 0506126
 Koch, Saueressig 1401.4452

ds2 = r2dω2 + 2dv dr − F(r)du2

F(r) = 1 − 2mr2 r3 + 2α2m

Eddington-Finkelstein coordinates

r = 2m r = rin

horizon trapped

r t r = 0

Effective theory

Vidotto, Rovelli 1401.6562 


! ! ! ! ! ! ! ! !

Hayward 0506126
 Koch, Saueressig 1401.4452

ds2 = r2dω2 + 2dv dr − F(r)du2

F(r) = 1 − 2mr2 r3 + 2α2m

Eddington-Finkelstein coordinates

mf < 1 √ 2mi

Different cases:

• 1. Hawking evaporation only
• 2. Bounce
• 3. Black to White Bounce

mf ∼ 1 √ 2mi tb ∼ m3

tb ∼ m2 mf ∼ mi

tb ∼ m3

mf < 1 √ 2mi

tb ∼ m3

t r = 2m r = rin r r = 0

• 1. Hawking evaporation only

no information paradox: no firewalls!

Vidotto, Rovelli 1401.6562

t r = 2m r = rin r r = 0

• 2. Bounce

no information paradox: no firewalls!

Vidotto, Rovelli 1401.6562

Sin = Slost

t = 0

mf ∼ 1 √ 2mi tb ∼ m3

Eburst = hc 2rf ∼ 3.9GeV

The bigger the BH, the lower is the emitted burst The only parameter is the initial mass of the BH

Mass-loss Rate

dm dt = −f(m) m2

• mass decreases
• temperature increases
• new particles produced

mi = ✓ 3 tHf(m) 1 − mf/mi ◆1/3

Halzen et al. Nature 353

rf ∼ 10−14cm

mi ∼ 6.1 × 1014g

mf ∼ 4.3 × 1014g

Integrated over Hubble time: Page time: mf/mi =

1 √ 2

f(m): the branching ratio 
 depends on the internal dof

f(m)

• 1. Which signal?
• 2. From where?
• 3. Of which origin?
• 4. Have we already seen it?

Experimental search for Planck Stars

Barrau, Rovelli 1404.5821

• 1. Which signal?

eGamma Entries 1001464 Mean 0.1068 RMS 0.1116

E(GeV) 0.1 0.2 0.3 0.4 0.5 N 1000 2000 3000 4000 5000 6000 7000 8000

eGamma Entries 1001464 Mean 0.1068 RMS 0.1116

uubar channel: energy spectrum of photons eCM = 3.9 GeV, event = 100000

Barrau, Rovelli 1404.5821

uu channel: mean energy spectrum 


• f secondary photons

MonteCarlo PYTHIA code 
 inputs: eCM=3.9 GeV 
 events=105

• The energy of most of the emitted photons is not Eburst

¯ Eγ ∼ 0.03 Eburst ∼ 10 MeV

How many photons?

eGamma

Entries 425453 Mean 0.03381 RMS 0.1401

E [GeV]

• 2

10

• 1

10 1

]

• 1

[GeV dE dN

• 2

10

• 1

10 1 10

10

10

10

10

eGamma

Entries 425453 Mean 0.03381 RMS 0.1401

energy spectrum of photons

Total particle emitted, each species according to # internal dof

n < Nburst >⇡ 4.7 ⇥ 1038.

direct emission

• 2. From where?

Maximal distance: Distribution:

Barrau, Rovelli 1404.5821

Rdet = r S < Nburst > 4πNmes . S=1m 2 Nmes=10 if ==> R det~200 light years

local isotropic

• 4. Of which origin?

Barrau, Rovelli 1404.5821

• black holes formed at the beginning of the universe 


(recombination time ~ 13.4 billion years ago)


• for mi ~ 1015g we have 


Primordial 
 Black Holes

Ndet < 4πρDM

∗

ΩP BH 3mf ✓S < Nburst > 4πNmes ◆ 3

2

⇡ 3.8 ⇥ 1014.

• ectrum. As th

P(k) / kn

dn dmi = αm

−1− 1+3w

1+w

i

,

dn dm ⇠ α h m− 5

2 Θ(m m∗) + m

− 9

2

∗

m2Θ(m∗ m) i

N(∆t) = R m(∆t)

mf dn dmdm

R mmax

mf dn dmdm ΩP BHN max det Ωsr,

• Assume a wide spectrum for PBH:



 
 
 Today’s spectrum:
 
 
 
 Expected detection in ∆t

up to one 
 event per day! formation at radiation dominated era

• 5. Have we already seen it?

Barrau, Rovelli 1404.5821

Diffuse Emission: Very Short GRB:

• short time scale
• local bubble origin
• harder spectrum

eGamma

Entries 425453 Mean 0.03381 RMS 0.1401

E [GeV]

• 2

• 1

]

• 1

[GeV dE dN

• 2

• 1

eGamma

Entries 425453 Mean 0.03381 RMS 0.1401

energy spectrum of photons

• integrated emission over huge distance
• the smaller BH, the higher the burst
• harder spectrum
• red shift dominates

• 1. Which signal?
• 2. From where? Local and Isotropic
• 3. How often? One event per day
• 4. Of which origin? Primordial Black Holes
• 5. Have we already seen it? Maybe: VSGRB

Experimental search for Planck Stars

¯ Eγ ∼ 0.03 Eburst ∼ MeV

r = 2m r = rin r t r = 0

• 3. Black to White Bounce

tb ∼ m2 mf ∼ mi

Haggard, Rovelli 1407.0989

The bigger the BH, the lower is the emitted burst
 (but bigger flux!)

r = 2m r = rin r t r = 0

• 3. Black to White Bounce

tb ∼ m2 mf ∼ mi

Haggard, Rovelli 1407.0989

The bigger the BH, the lower is the emitted burst
 (but bigger flux!)

Quantum pressure Planck density object
 radius >> Planck length quantum effects appear at asymptotic proper time emission at

r

=

t = 0

• r=const 


space-like in the trapped region

quantum tunneling

• Black to White Bounce Phenomenology

Eburst ∼ 10MeV

⌧ ∼ m2 `P

r ∼ 7 6 2m rb ∼ ✓ m mP ◆ 1

3

`P

Hájíček, Kiefer 0107102

horizon trapped

t = 0

quantum
 region

Haggard, Rovelli 1407.0989

• 1. Which signal?
• 2. From where? Isotropic (close or distant)
• 3. How often? TBC, but enough…
• 4. Of which origin? Primordial Black Holes
• 5. Have we already seen it? Maybe: Fast X-ray Burst

Experimental search for Planck Stars v2.0

Eburst ∼ 10MeV

!

Effective repulsive force Size Planck length

!

BH are bounce in slow motion Quantum Gravity Phenomenology!

• Summary
• 1. Which signal?
• 2. From where?
• 3. How often?
• 4. Of which origin? Primordial Black Holes
• 5. Have we already seen it?

Eburst ∼ 3.9 GeV

Local and Isotropic One event per day

VSGRB

!

Effective repulsive force Size Planck length

!

BH are bounce in slow motion Quantum Gravity Phenomenology!

• Metric for Black-to-White process

Quantum Tunneling

Summary

• 1. Which signal?
• 2. From where?
• 3. How often?
• 4. Of which origin? Primordial Black Holes
• 5. Have we already seen it?

Eburst ∼ 3.9 GeV

Local and Isotropic One event per day

VSGRB

Eburst ∼ 10MeV

Fast x-ray Burst

?