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 No need to violate SEC ! Loop Quantum Gravity is a theory about spacetime quanta: 1.6 SU(2) group variables canonical 1.4 | ! (v, " )| | ! (v, " )| ! 2 1.2 sin( λγ ˙ a ) 3 a 1.5 1 a 3 + H matt Minimal area gap 0.8 H e ff = − 1 0.6 8 π G λγ 0.4 0.5 0.2 Hamiltonian constraint 0 0 5*10 3 1.0*10 4 -1.2 Holonomy corrections 1.5*10 4 -1 a 2 ✓ ◆ a 2 = 8 π G ˙ 2.0*10 4 1 − ρ -0.8 2.5*10 4 v -0.6 3.0*10 4 ρ -0.4 " 3.5*10 4 3 -0.2 ρ c 4.0*10 4 t K + �~ ~ L = 0 P 0 covariant SU(2) group variables Boost generator Rotation generator Minimal area gap z Simplicity constraint � = 1 /a Maximal acceleration W ( η , j ) = h j, j | Y † e i η K z Y | j, j i P { motion of an accelerated observer in spacetime Rovelli,Vidotto 1307.3228 evolution of spacetime seen by an observer

What have we learnt from Loop Quantum Cosmology ? 0 quantum classical Big Bounce expanding 
 -0.2 solution Quantum Tunneling -0.4 superposition Effective repulsive force -0.6 Planck density φ -0.8 Size Planck length � V b ∼ m ` 3 P ≈ 10 24 cm 3 m P -1 contracting 
 solution -1.2 Ashtekar,Pawlowski, Singh, Vandersloot 0612104 ! ! see talks by Grain and Martin-Benito ! 1*10 4 2*10 4 3*10 4 4*10 4 5*10 4 0 V v v

Where does matter falling into a Black Hole go? Planck Stars Quantum Tunneling superposition Effective repulsive force Planck density Size Planck length � r b ∼ m ` P m P Rovelli, Vidotto 1401.6562 ! ! See works by Barrau, De Lorenzo, Haggard, Pacillo, Rovelli, Speziale, Vidotto… see talk by Rovelli See also related works by Bianchi, Smerlak, Perez, Gosh, Frodden, Gambini, Pullin…

Effective theory Vidotto, Rovelli 1401.6562 
 ! t ! Eddington-Finkelstein coordinates ! ! ds 2 = r 2 d ω 2 + 2 dv dr − F ( r ) du 2 ! ! horizon ! 2 mr 2 F ( r ) = 1 − F ( r ) = (1 − 2 m/r ) ! r 3 + 2 α 2 m ! Hayward 0506126 
 Koch, Saueressig 1401.4452 r = 0 r = r in r = 2 m r

Effective theory Vidotto, Rovelli 1401.6562 
 ! t ! Eddington-Finkelstein coordinates ! ! ds 2 = r 2 d ω 2 + 2 dv dr − F ( r ) du 2 ! ! horizon ! 2 mr 2 F ( r ) = 1 − ! r 3 + 2 α 2 m ! Hayward 0506126 
 Koch, Saueressig 1401.4452 r = 0 r = r in r = 2 m r

Effective theory Vidotto, Rovelli 1401.6562 
 ! t ! Eddington-Finkelstein coordinates ! ! ds 2 = r 2 d ω 2 + 2 dv dr − F ( r ) du 2 ! trapped ! horizon ! 2 mr 2 F ( r ) = 1 − ! r 3 + 2 α 2 m ! Hayward 0506126 
 Koch, Saueressig 1401.4452 r = 0 r = r in r = 2 m r

Different cases: 1. Hawking evaporation only 2. Bounce 3. Black to White Bounce 1 1 t b ∼ m 3 t b ∼ m 3 t b ∼ m 2 m f < 2 m i m f ∼ 2 m i m f ∼ m i √ √

1. Hawking evaporation only Vidotto, Rovelli 1401.6562 1 t b ∼ m 3 m f < 2 m i t √ no information paradox: no firewalls! r = 0 r = r in r = 2 m r

2. Bounce Vidotto, Rovelli 1401.6562 1 t b ∼ m 3 m f ∼ 2 m i √ t no information paradox: no firewalls! t = 0 S in = S lost r = 0 r = r in r = 2 m r

Mass-loss Rate Halzen et al. Nature 353 • mass decreases dt = − f ( m ) dm • temperature increases m 2 • new particles produced ✓ 3 t H f ( m ) f(m): the branching ratio 
 ◆ 1 / 3 f ( m ) depends on the internal dof Integrated over Hubble time: m i = 1 − m f /m i 1 Page time: m f /m i = √ 2 The only parameter is the initial mass of the BH m f ∼ 4 . 3 × 10 14 g r f ∼ 10 − 14 cm m i ∼ 6 . 1 × 10 14 g E burst = hc The bigger the BH, ∼ 3 . 9 GeV the lower is the emitted burst 2 r f

Experimental search for Planck Stars 1. Which signal? 2. From where? 3. Of which origin? 4. Have we already seen it? Barrau, Rovelli 1404.5821

1. Which signal? Barrau, Rovelli 1404.5821 The energy of most of the emitted photons is not E burst uubar channel: energy spectrum of photons eCM = 3.9 GeV, event = 100000 - N uu channel: eGamma eGamma Entries Entries 1001464 1001464 mean energy spectrum 
 8000 Mean Mean 0.1068 0.1068 0.1116 0.1116 RMS RMS of secondary photons 7000 MonteCarlo PYTHIA code 
 6000 inputs: eCM=3.9 GeV 
 5000 ¯ events=10 5 E γ ∼ 0 . 03 E burst ∼ 10 MeV 4000 3000 2000 1000 0 0 0.1 0.2 0.3 0.4 0.5 E(GeV)

How many photons? Total particle emitted, each species according to # internal dof n < N burst > ⇡ 4 . 7 ⇥ 10 38 . direct emission energy spectrum of photons eGamma eGamma 5 ] 10 -1 [GeV Entries 425453 Entries 425453 dN 4 dE 10 Mean 0.03381 Mean 0.03381 RMS RMS 0.1401 0.1401 3 10 2 10 10 1 -1 10 -2 10 -2 -1 10 10 1 E [GeV]

2. From where? Barrau, Rovelli 1404.5821 r S < N burst > R det = . 4 π N mes S=1m 2 Maximal distance: if == > R det ~200 light years N mes =10 local Distribution: isotropic


 
 
 
 
 
 4. Of which origin? Barrau, Rovelli 1404.5821 Primordial 
 • black holes formed at the beginning of the universe 
 (recombination time ~ 13.4 billion years ago) 
 Black Holes ◆ 3 N det < 4 πρ DM Ω P BH ✓ S < N burst > 2 • for m i ~ 10 15 g we have 
 ⇡ 3 . 8 ⇥ 10 14 . ∗ 3 m f 4 π N mes ectrum. As th P ( k ) / k n d n − 1 − 1+3 w • Assume a wide spectrum for PBH: 
 formation at radiation dominated era 1+ w = α m , i d m i d n − 9 h i m − 5 m 2 Θ ( m ∗ � m ) 2 Θ ( m � m ∗ ) + m Today’s spectrum: 
 2 d m ⇠ α ∗ R m ( ∆ t ) d n d m d m up to one 
 m f Expected detection in ∆ t d m d m Ω P BH N max N ( ∆ t ) = det Ω sr , R m max event per day! d n m f

5. Have we already seen it? Barrau, Rovelli 1404.5821 • short time scale Very Short GRB: • local bubble origin • harder spectrum energy spectrum of photons eGamma eGamma 5 10 ] -1 [GeV Entries 425453 Entries 425453 dN dE 4 10 Mean 0.03381 Mean 0.03381 Diffuse Emission: RMS RMS 0.1401 0.1401 3 10 • integrated emission over huge distance 2 10 • the smaller BH, the higher the burst • harder spectrum 10 • red shift dominates 1 -1 10 -2 10 -2 -1 10 10 1 E [GeV]

Experimental search for Planck Stars ¯ 1. Which signal? E γ ∼ 0 . 03 E burst ∼ MeV 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

3. Black to White Bounce Haggard, Rovelli 1407.0989 t b ∼ m 2 t m f ∼ m i The bigger the BH, the lower is the emitted burst 
 (but bigger flux!) r = 0 r = r in r = 2 m r

3. Black to White Bounce Haggard, Rovelli 1407.0989 t b ∼ m 2 t m f ∼ m i The bigger the BH, the lower is the emitted burst 
 (but bigger flux!) r = 0 r = r in r = 2 m r

Black to White Bounce Phenomenology Hájí č ek, Kiefer 0107102 Haggard, Rovelli 1407.0989 quantum 
 region quantum tunneling Quantum pressure Planck density object 
 ✓ m ◆ 1 3 ` P radius >> Planck length r b ∼ • m P t = 0 t = 0 • r ∼ 7 quantum effects appear at 6 2 m trapped • horizon ⌧ ∼ m 2 asymptotic proper time ` P 0 = r emission at E burst ∼ 10 MeV r=const 
 space-like in the trapped region

Experimental search for Planck Stars v2.0 1. Which signal? E burst ∼ 10 MeV 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

Summary ! ! Effective repulsive force BH are bounce in slow motion Size Planck length Quantum Gravity Phenomenology! � 1. Which signal? E burst ∼ 3 . 9 GeV Local and Isotropic 2. From where? 3. How often? One event per day 4. Of which origin? Primordial Black Holes VSGRB 5. Have we already seen it?

Summary Quantum Tunneling Metric for Black-to-White process ! ! Effective repulsive force BH are bounce in slow motion Size Planck length Quantum Gravity Phenomenology! � 1. Which signal? E burst ∼ 3 . 9 GeV E burst ∼ 10 MeV Local and Isotropic 2. From where? ? 3. How often? One event per day 4. Of which origin? Primordial Black Holes VSGRB Fast x-ray Burst 5. Have we already seen it?