Conference Note: The 49th Yamada Conference
Black Hole and High Energy Astrophysics

at Kyoto, April 6-10, 98

The official page of this conference. (If it still exists.)
This conference was for celebrating 60th birthday of Prof. Humitaka Sato, Kyoto University. Yamada is the name of sponser. All talks were invited ones. All talks were within 40 minutes. Presented field was wide; cosmology, relativity, cosmic rays, stars, clouds, ...
No abstract book. The proceedings will be published.
The followings are from my personal notebook. Readers are recommended not to believe all words.

J. Silk "Galaxy Formation"
A review of galaxy formation process. So far, we are succeeded to model 
clustering of galaxy, halos, and intergalactic medium, but we are failed
to model disk sizes and dwarf rotation curves. We have a model of chemical
evolution but do not have a role of merging, star formation rate. He, then,
introduced his work astroph/9710291. 

O. Lahav  "How smooth is the universe on large scales ?"
He first introduced several observation projects such as SDSS (US-Japan), 
2dF (UK-Australia) for wide-field search and IRAS for X-ray background. 
He next showed his recent fractal dimensional analysis (Wu-Lahav-Rees 98)
and concluded FRW is good enough for over 300Mpc. As open questions, he
mentioned biasing parameter and intermedium scale structure (100-1000Mpc). 

Li-Zhi Fang "Cosmology with high redshift objects" 
He showed his efforts to combine non-Gaussianity in modelling power spectrum
P(k), but his conclusion was not clear. He cited Trostoy's sentence in his
final slide that "simple matter (Gaussian) is easy to handle, but complex
matters (non-Gaussian) are hard to cooperate".

R. Wald "A New Method for Determining Gravitational Lensing
         Effects in Inhomogeneous Universes" 
He showed his study of statistical treatment of lensing effect of null 
congruence (astroph/9708036). Area magnification - redshift relation is
characterized mainly by minimum angular size of the lensing objects if
we fix their proper size of each inhomegenious balls in FRW. 

S. Ikeuchi "Formation of Cosmic Structures from Lyman Alpha Forest to 
A review of Lyman alpha absorption by clouds in observation and theory.
From observation, we can say that Lyman alpha clouds are certainly the
seed of galaxies; proto globular cluster clouds are good agreement with 
Lyman alpha clouds in mass and metal abundance. Self-similar structure 
between galaxy-LMC-GC is suggested.  He mentioned his scenario:
 to z=10 : reheating phase, collapse of dust, ionization and metal pollution
z=10 to 3: non-linear growth phase, inclease UV flux from QSOs, clustering
of clouds to dwarfs, collapse to bright galaxies
z=3 to 0 : hierarchical clustering to galaxies and LSS: decrease of UV flux, 
collapse to GC and dwarfs, collapse to Ly alpha clouds. 

M. Fukugita "Observation of cosmological parameters" 
He summarized recent progress of determining cosmological parameters. 
Hubble constant.
After the Hipparcos(97-98), all the situation has been changed.  Since 
Hipparcos has high-resolution, we can now skip some cosmic ladder. 
However the distance to LMC is more uncertain (18.00-18.80Mpc) than 
before(18.35-18.65Mpc). From the distance to Pleiades, Hipparcos shows 
Hubble is 70 \pm 10 with 15-20% error. 
Hubble-age matching suggest omega=1. Potent preferes high omega. But
all others (direct sum, baryon fraction mathcing, galactic clustering)
suggest low omega 0.1-0.3. 
Recently most distant (z=5.3) SNeIa was discovered. The fitting of SNeIa
diagram was shifted slightly, suggesting lambda=0.8. Constraint from lensing
is still lacking of data. Clustering dynamics also support lambda=0.7-0.8.
Open questions.
reliability of stellar evolutio theory/ SNeIa systematic error/ Lensing statistics

M. Turner "Beyond the Hot Big Bang: Inflation and Cold Dark Matter"  
He showed his plays of parameters of CMB, inflationary models, CDMs. 
In flat spacetime, most plausible CDM models are:
if Hubble < 55, then simple-CDM. 
if neutrino mass is around 4eV, then nu-CDM.
if accel. parameter is around half, then Lambda-CDM.
if massive unstable tau neutrino exists, then tau-CDM. 

K. Sato "BBN as a probe of the early universe"  
Recent update of BBN. 
Blue compact dwarf galaxies suggests high He abundance than before.
QSO data suggest low D/H, apart from previous COBE range. 
Therefore allowed \eta parameter is two ranges, 2.3-2.6 or 4.7-5.8 times
10^{-9}.  However, low He-low D/H gives crises in neutrino generation and
lepton number assainments. 

A. Dolgov "Nonequilibrium cosmic neutrinos and nucleosynthesis."  
It was hard for me to understand what he wanted to say. Sorry. 

A. Krasinski "Physics and cosmology in an inhomogeneous Universe"  
A review of cosmological model embedding Lemetre-Tolman-Bondi metric
in FLRW. matching model/null propagation/void evolution were shown. 
He also showed some his summarization of exact solutions (which is now
in his book).

G.F.R. Ellis "Consistency of inhomogeneous solutions, 
                 and the nature of the Newtonian Limit" 
He explained his 3+1 covariant formulation of GR, based on Lagrangian 
scheme. In the shear-free dust case (Ellis 67, Szekeres et al 97), 
Newtonian limit of GR has bounce solution, which is not the same as 
Newton's picture. He also mentioned irrotational and shear-free case
(quasi-Newtonian, or silent universe), especially lapse condition for
consistent evolution upto secondary condition of constraints. 

R. Ruffini "Beyond the Critical Mass" 
He reviewed energy extraction methods from BH, mainly citing his works in 
70's.  The word "dyadosphere" was introduced, where dyado means pair in 

S. Tsuruta "Black Holes and Active Galactic Nuclei" 
She reviewed "Best Buy" model of AGN recently discussed by Rees (97). 
Also mentioned the controvocy of AGN observed by ASCA, whether we need Kerr
BH or not. MHD calculation in Kerr background (Nitta et al) was introduced.
She summarize that GR effect now should be considered in AGN model.

A. Vilenkin  "Open universes, inflation, and the anthropic principle" 
His talk was on open inflationary models.  He mentioned that two scalar 
field model have difficulty of inhomogeneity inside a bubble 
(GarciaBellido et al).  Using the principle of mediocrity, he explains
how plausible the open universe is.  Finally he talked the recent 
Hawking-Turok (98)'s model of quantum creation of open universe, pointing
out the problem of asymptotically thorny instanton. 

T. Piran "Gamma-Ray Bursts" 
He explains his fireball model as a source of gamma ray burst. The 
mechanizm is from internal shocks within relativistic flow. The GRB 
afterglow line of Feb28/97 event agrees with fireball model with ISM. 
Inside a fireball, a binary NSs is the best candidate.

W. Press "Not a Gamma Ray Burst Model" 
Began the explanation of violin string in moving syrup (J.R. Pierce, 50s),
which says that superluminal dissipation is anti-dissipative, he explained
superradiance of a rotating conductor (Zeldvich, 71) next.  He, then, 
explained his toy model of spinning double rings with close to the speed
of light made by graphite and super conducter.  He showed the existence of
unstable mode, and speculated further study of BH-electromagnetic dynamics
for explaining a gamma-ray burst.

T. Nakamura "Coalescing neutron stars/ black holes"
Three topics.  (1) A work with H. Sato, numerical simulation of axisymmetric
star collapse, PLA86(81)318. (2) Latest status of NS-NS coalescing 
simulation, but not in detail. (3) As a discussion of event rate, he 
explained his model, ApJ487(97)L139, that if the sources of MACHO are 
primordial BHs then we only need to assume that 5 10^{-4} of our halo is

B. Schutz "GWs: Crossing the "milli-atto" Threshold"
"milli-atto" means 10^{-3} times 10^{-18}. 
He summerized the recent status of the GW detectors, interferometers, 
bars, and LISA.  The sensitivities are (S/N=5)
   3Mpc  8Mpc  25Mpc  23Mpc  900Mpc for 2 NSs of 1.4 M_{solar}
   -     24Mpc 125Mpc 120Mpc 4Gpc   for 2 BHs of 10 M_{solar}
He also commented recent progress of the new unstable model of star, 
r-modes, by Andersson (97), Lindblom et al(98) and Owen et al (98); 
and accreting NSs by Bildsten (98). 

K. Thorne "Probing black holes with gravitational waves"
Topics related data analysis at LIGO and LISA. Mainly introduced recent 
works by Flanagan et al [PRD57(98)] (Mpc-totalmass, S/N-totalmass) and 
Brady et al (98) (extrapolate higher PN region by Pade approx.).  He also
commented on the issue of the dQ/dt (Q=Carter constant) related with 
recent radiation reaction analysis by Mino et al and Wald et al.

B. Carr "Cosmic Rays from Primordial Black Holes"
A review of primodial BHs. Original model and consequences / 
formation from inhomogeneities / evapolation and upper limits, with full
of reference list.  Some model can explain BATSE bursts, but needs 
fine-tuning of parameters.   

K. Koyama "X-ray sky observed with ASCA" 
A review of obserbations with ASCA. Star formation / SNR / galactic
halo / AGN / cosmic Xray background were shown. 

Y. Totsuka "Do neutrinos have a mass? -- some hints from Super-Kamiokande--" 
A review of obserbations with Super-Kamiokande. The problem of solar 
neutrino / oscilation model / degenerate mass scenario were commented. 

T. Kifune "Very High Energy Gamma Ray Astronomy"
A review of obserbations with EGRET/CANGAROO (10^{15} eV around).  
TeV gamma-ray / AGN burst / SNR / "cosmic cascade" were given.  

P. Yock "Japan/NZ Gravitational Microlensing Experiment"
A report of obserbations with MOA. 

M. Nagano  "Astrophysics of extremely high energy cosmic rays"
A review of obserbations with AKENO/AGASA  (10^{19} eV around).
galactic wid shock / AGN hot spot / cosmological GRB were commented. 

H. Sato "TBA"
Started from the question that we can see 10^{20} eV cosmic ray or not, 
his talk went historical one (Sato-Tati, PTP47(72)1788), ended with 
general comments on the relation between physics laws and the Universe. 
Since physicists are needed to bridge them, his conclusion was that
physics in the Universe needs us. 

W. Unruh "Black Hole Thermodynamics: Dumb Holes and Entropy"
Two approaches to thermal emission by BH were reviewed. One is the 
dissipation model of high frequency modes by Jacobson, which occurs outside 
of the horizon. The other is explanation of BH entropy carried in 
D-branes, which is internal string phenomenon. 

W. Israel "Gedanken experiments in black hole thermodynamics"
A historical review of BH thermo dynamics.  Some recent BH entropy models
were also referred. 

J. Hartle  "Black Hole Evaporation in Generalized Quantum Theory"
He proposed a generalized quantum theoretical approach, which has three 
processes; fine-grained histries / coarse-grainings / decoherence 
functional as a measure of interference, and which does not requre state / 
causal structure nor fixed geometry.  From the sence of 4d foliation, he 
said that information loss is a problem of 3-slice. 

C. Hoenselaers "The long road to exact solutions"
After introducing Baecklund transformation, he showed sample solutions 
from Kerr seed, double Kerr and rotating disk of dust. 

A. Tomimatsu "A Short Review of Tomimatsu-Sato Metrics:
              from Spinning Masses to Gravitational Waves"
A historical review of Tomimatsu-Sato solution.  He omitted the topics in 
the proceedings of MG2. Extention of parameters, and plane/cylindrical 
limits of TS solutions were reviewed. 
F. Ernst "Thirty years of complex potentials"
A historical review of complex potentials. Related all topics and references
were given. 

R. Penrose "Quantum State Reduction as a Gravitational
            Phenomenon:  Theory and experiment"
He started from a question of superpositon of spacetime, and mentioned his
approach by taking a measure of ill-definedness, GRG28(96)581, 600.  A 
limit of the theory of combined Newton-Cartan and QM might be discussed.               

Last updated: April 15, 1998 / Hisaaki Shinkai / shinkai@wurel.wustl.edu