=== Christian Ott - GWs from core-collapse supernovae ===

- red giants, 1 SN/40 yr in Milky way, 1 SN/2 yr at 3.5 Mpc
- most stars below 20 Msun explode
- iron core collapse only halted by neutron degeneracy pressure
- inner core bounce, hydrodynamic shock, but loses energy to neutrinos and dissociation: stalls
- how to revive the shock and get a SN? (otherwise get a BH directly, collapsar)
- most of energy into neutrinos either way

- simulations need multiphysics: MHD, GR, neutrino transport and microphysics, equation of state

- possible mechanisms for blow up:
	- 2D/3D neutrino mechanism (nu energy deposition, convection/standing accretion-shock instability)
	- MHD-jet mechanisms (rapid rotation, B-field amplification)
	- g-mode excitation

- GW emission
	- spin up and rotational deformation of inner core: core bounce gives infall/plunge-bounce/quick ringdown within 10 ms, axisymmetric, range of frequencies depending on initial rotation and EOS
	- dynamical rotational 3D instabilities: m=2, dynamical instability at T/|W| = 0.27, secular at 0.14 for NG, roughly for GR; but protoneutron star may reach a rotational barrier before reaching sufficient rotations
		- however: low-T/|W| dynamical corotation instability still possible; complicated waves 50 ms after plunge
	- standing accretion-shock instability (SASI): white-noise burst
	- GWs from anisotropic neutrino emission: mostly "memory" waveform
	- PNS l=1 g-mode excited by SASI; real? interesting TF evolution tracks the evolution of the PNS

- connection between mechanisms and emission (but may mix)
	- neutrino -> weak
	- MHD      -> 3D instability, collapse and bounce
	- acoustic -> g-modes

- detection prospects: poor SNR at 4 Mpc with advanced LIGO
	- x10 sensitivity improvement at 500-1000 Hz needed for detection, x100 for physics

=== Kate Scholberg - supernova neutrinos and GWs ===

- with collapse, 99% of binding energy of PNS goes into nus of all flavors
- many nu detectors online sensitive to bursts in the Galaxy (7000 events), perhaps beyond
- some pointing possible from elastic scattering, perhaps 4 deg with Super-K
- SNEWS: supernova early warning systems, with 10-s coincidence between detector event datagrams
- GW--low-energy-nu offline coincidence analysis

=== Szabi Marka - GW and HEN ===

- GW and HEN as cosmic messengers
	- both have negligible absorption -> travel cosmological distances
	- are not deflected by magnetic fields -> can be traced back
	- are weakly interacting -> escape from dense objects
- source candidates
	- long GRBs
- detectors
	- neutrino converted to charged particle in bulk of Earth; charged particle Cherenkov radiation in water or ice detected
	- northern emisphere detectors see neutrinos from southern sky, and vice versa
	- Antares/Baikal/Amanda-IceCube complementarily cover the sky
	- angular resolution is 1.5 deg
- coincidence searches interesting with existing, future detectors
	- papers by Aso et al. in CQG
	- enables significant science inaccessible to single detector
	- S5/VSR1 and S6/VSR2 searches in progress

=== Larry Price - searching for stochastic backgrounds with interferometry and pulsar timing ===

- definition of stochastic background---Allen and Romano: many uncorrelated sources, stationary, isotropic, unpolarized
- cosmological (inflation, cosmic strings, preheating, phase transitions) and astrophysical (BH, NS binaries)
- pulsar timing as GW detectors

- optimal statistic for stochastic background: start with correlation-with-kernel of detector outputs, maximize SNR (or work from ML formalism)
- for pulsars the overlap reduction function is more complicated
- for multiple detectors, use a weighted sum of the individual detector-pair statistics

- relax isotropic assumption, and do skymap: PTA has most SNR in southern hemisphere (can also see locations of pulsars)
- can also do point-spread function

- Arecibo remote command center (@UTB, @UWM)
- activities: P-ALFA observing, candidate viewing, pipeline development

=== Eric Thrane - directional searches for stochastic gravitational-wave background with LIGO ===

- spherical harmonic decomposition algorithm
	- unifies isotropic/monopole and radiometer/l_inf searches
	- accommodates arbitrary angular distributions
- ML analysis yields estimates of SH-basis coefficients
- natural basis diagonalizes Fisher matrix: shows which modes a given baseline is most sensitive to
- regularize sky maps by removing least-sensitive eigenvectors; bias introduced
- useful to studying how sensitivity improves with additional detectors
- Romano and Yu generalizing to LISA

=== Teviet Creighton - pulsar timing near supermassive black holes ===

- arXiv:0812.2302
- SMBHs are everywhere and pulsar timing can probe their geometry
- follow geodesics of photons around Schwarzschild
- pulses of NS orbiting black hole have different intensities and times of arrival along different propagation routes
- pulse intensities and times of arrival can be determined from two universal functions

=== Ben Owen - How photon astronomy affects searches for continuous
gravitational waves ===

- how?
	- indirect upper limits
	- look for things better if we know about them
	- theories for NS formation and GW emission affect where we look
	- our interpretation also informed by photon observations

- four types of searches
	- known (position and frequency evolution)
		- indirect spindown limit (highest at 1e-24)
	- unseen (could use infinite computing power)
		- indirect limit, use supernova rate and population model
	- accreting NS (position known, search over orbit and frequencies)
		- indirect limit, assume accretion/GW torque balance (highest at 2e-26)
	- nonpulsing NS (position known, search over frequencies)
		- indirect spindown limit, includes age of NS (highest at 1e-24)

- finding things
	- SNR grows as T^1/2
	- if parameters not know, cost may scale as T^7
	- incoherent integration stretches gains as N^1/4

- results (known pulsars)
	- 1/S1, 28/S2, 78/S3-S4, Crab spindown limit ApJL 2008
	- currently ~100 of 200 pulsars in band, need timing for rest
	- for some known pulsars, ellipticity constrain would reach physical range
	- need good timing
- results (unseen stars)
	- best result ten times worse than for known pulsars
	- S5 8 mos semicoherent (30 min stretches), h < 1e-24 over 200 Hz band (arXiv)
- results (accreting)
	- S2/S4 Sco X-1
	- would need period (look for it in RXTE data)

- directed searches (in progress)
	- supernova remnants
	- "empty" supernovae
	- massive starforming regions
	- globular clusters
	- funny point sources
	- ...

- theory
	- interpretation of upper limits: cannot constrain EOS unless we understand mountain building
	- interpretation of detections: high ellipticity, frequency ratio

=== Badri Khrishnan - detecting gravitational waves from accreting neutron stars ===

- observed accreting NS spin much slower than they could; break-up frequencies expected > 1 kHz
- it is hoped that reason is GW emission
	- Bildsten: balance accretion and GW torques
	- flux and frequency yield h0

- sources with spin-frequency measurements
	- ms pulsars (10 sources)
	- burst oscillations (12+7)
	- kHz QPO (9)

- search techniques
	- coherent integration
	- semicoherent techniques, incl. semicoherent powerflux
	- cross-correlation method (Dhurandhar, Khrishnan et al. 2007)

- more realistic detectability estimate (Watts et al. MNRAS 2008)
	- account for statistical and computational hits
	- spin uncertainty is main problem
	- four sources detectable by Advanced LIGO

=== Szabi Marka - GWs and multimessenger astrophysics ===

- gravitational-wave sources: transients, repeaters, continuous
- modeled/unmodeled, targeted/all-sky

- possible multimessenger triggers: GRB, optical, radio, X-ray, neutrino transients
- give correlations in time/direction, information on source properties/galaxy host/distance