From Quarks to the Cosmos:
Forefront Problems at the Intersection of Astrophysics, Cosmology, Nuclear Physics and Particle Physics

The 2nd-Workshop (15-16 December 2010):
“Recent Progresses in Dark-Universe and Astrophysics”

Yong-Yeon Keum
IEU/Ewha WomansU.
Seoktae Koh
CQUST/Sogang U.
Scientific Secretary 
Sungwon Kim
Ewha Womans U.
Sangpyo Kim
Kunsan U. and APCTP
Sinkyu Kang
Pyungwon Ko
Hongjoo Kim
Jaesam Kim
Tae-Hoon Lee
Sungsil U.
Kyungjin Ahn
Kunsan U.
Jai-Chan Hwang
Myung-Gu Park
Jean Iliopoulos
IOC (chair)
Hitoshi Murayama
Asanta Cooray
T. Kajino
NAOJ and Tokyo U/Japan
G.J. Mathews
A. Yu Smirnov
M. Turner
Fermilab and Chicago/USA


APCTP Seoul Branch Office (Please see the map in below)

Address: Yuksam-Dong 635-4, KOFST New-Building 11 floor
Near Gangnam-Station,  Exit-No. 8
Direction of Kukgiwon

135-703 서울시 강남구 역삼동 635-4 한국과학기술단체총연합회 신관 11
: 02-561-7641~2, Fax: 02-561-7640

Scope of Program

This topical program: Connections from Quarks to the Cosmos is proposing to emphasize the growing importance of Astrophysics and Cosmology to Subatomic Physics and conversely. This program will focus on several of the “Science Questions” including the nature of Dark-Matter and Dark-Energy, Neutrino Properties and their relevance to the evolution of the Universe, Cosmic Accelerators, and the origin of the heavy elements.

Special Request to the Korean Participants

I would like to ask invited Korean speakers to send me the information of your bank account, except Foreign speakers. Seminar fees (200,000/150,000/100,000 Won) will transfer your bank account directly from APCTP around 10 days later after workshop.
In addition I would like to ask you to write me a short note of your interest to attend the workshop dinner in order to help to reserve a reasonable restaurant near the Gangnam subway station.


December 15, 2010:

10:30-11:30:  Kiyotomo Ichiki: Weak lensing and Massive Neutinos
11:30-12:30:  Keiich Umetsu: Galaxy Cluster Gravitational Lensing as a Cosmological Probe

12:30-14:00:  Lunch

14:00-15:00:  Yong-Yeon Keum: GRB-Cosmology Projects and Origin of Dark-Energy
15:00-16:00:  Jai-Chan Hwang: TBA

16:00-16:30:  Coffee Break

16:30-17:30:  Bum-Suk Kae : TBA
17:30-18:00:  Jong-Chul Park:TBA

18:30-21:00:  Workshop Dinner

December 16, 2010:

10:30-11:30:  Kiyoung Choi: Local non-Gaussianity from multi-field inflation
11:30-12:30:  Frederico Arroja: Non-Gaussanity

12:30-14:00:  Lunch

14:00-15:00:  Yuichi Takamizu: Beyond delta-N formalism for a single scalar field
15:00-16:00:  :Shuichiro Yokoyama: Iso-curvature fluctuations in modulated reheating scenario

16:00-16:30:  Coffee Break:

16:30-17:15:  Seok-Tae Koh: Non-minimally coupled Hybrid inflation
17:15-17:45:  Yoshitaka Takkeuchi: Impacts of the LSS-CMB lensing and LSS-galaxy lensing cross-correlations for constraints on primordial non-Gaussianity

17:45-17:50:  Yong-Yeon Keum: Closing Remarks

Weak Lensing and Massive Neutinos
Speaker: Kiyotomo Ichiki (Nagoya U/Japan)

Abstract: Cosmic neutrinos with finite masses constitute some portion of dark matter and have played important roles in cosmological structure formation. However, to place a constraint on neutrino masses from cosmological observations such as the weak lensing, one has to
construct precise models for both sides of theory and observation. For
the theory side we are developing a simple model of spherical collapse
of  overdensity including massive neutrinos. 
We plan to present its application for determining neutrino masses from cosmological observations.  For observational side, we recently propose a use of statistical tool called copula for the weak lensing likelihood function. We present how well the copula likelihood can reproduce the result of ray-tracing simulations, with a brief introduction of copula.

GRB Cosmology Project and Origin of Dark-Energy
Speaker: Yong-Yeon Keum (IEU, Ewha Womans University)

Abstract: We use both SNe-Ia type data and the measurement of Gamma Ray Burst(GRB) distances to constrain dark-energy cosmological model parameters. One of the interesting way for the improvement of our understanding on how dark-energy behaves is to study the evolution of the universe at redshifts higher than those probed by SNe-Ia (z < 1.76). This requires standard candles that are visible at great distances. GRBs could in principle serve as such high redshift stanardizable candles. In our analysis we employ two different calibrating methods: fitting luminosity relation of GRB in each cosmology and using distance measures computed from binned GRB data: Amati-method vs Yonetoku-relation. We also discuss the general aspect of this GRB-cosmology project.


Impacts of the LSS_CMB lensing and LSS-galaxy lensing cross-correlations for constraints on primordial non-Gaussianity
Speaker: Yoshitaka Takeuchi (Nagoya U/Japan)

Abstract: Recent studies have shown that the primordial non-Gaussianity affects clustering of dark matter halos through a scale-dependent bias and various constraints on the non-Gaussianity through this scale-dependent bias have been placed. Here we introduce the cross-correlation between the galaxy angular distribution and the CMB lensing potential or galaxy lensing to effectively extract information about the bias from the galaxy distribution. Then, we estimate the error of non-linear parameter, f_NL, for the on-going CMB experiments and galaxy surveys, such as Planck and Hyper Suprime-Cam (HSC). We find that these cross-correlations help to reach the bottom of primordial non-Gaussianity.

Iso-curvature fluctuations in modulated reheating scenario
Speaker: Shuichiro Yokoyama (Nagoya U/Japan)

Abstract; Recently, primordial non-Gaussianity of curvature fluctuations has been focused on as a new probe of the physics of the early Universe.
Modulated reheating model has been known as one of the interesting scenarios generating large primordial non-Gaussianity, where the generation of the curvature fluctuations can be induced from the spatial inhomogeneity of the reheating.
We consider the gravitino dark matter scenario and also Affleck-Dine scenario in the modulated reheating model and find that these scenarios do not work very well due to the large DM/Baryon iso-curvature fluctuations.

Galaxy Cluster Gravitational Lensing as a Cosmological Probe
Speaker: Keiichi Umetsu (Academia Sinica/Taiwan)

Clusters of galaxies, by virtue of their position at the high end of the cosmic mass power spectrum, play a direct and fundamental role in testing cosmological models and in constraining the properties of dark matter (DM), providing unique and independent tests of any viable cosmology and structure formation scenario.  The ability of massive clusters, dominated by invisible DM (~80% in the mass), to significantly distort the images of background objects via gravitational lensing, and hence reveal their gravitational potentials and total mass profiles, can provide direct and unique constraints on the nature of the underlying matter distribution.
In this talk, I will present our recent comprehensive weak and strong gravitational lensing work on massive clusters based on deep Subaru/Suprime-Cam and Hubble Space Telescope/Advanced Camera for Surveys observations, aiming for constraining the representative DM mass profile shapes and mass concentrations as a function of the cluster mass.  Finally, I will discuss the prospects for the upcoming Cluster Lensing And Supernova survey with Hubble (CLASH), a 524-orbit HST multi-cycle treasury (MCT) program.

Local non-Gaussianity from multi-field inflation
Speaker:  Ki-Young Choi

Abstract: Large Local type non-Gaussianity can be generated during or after the end of inflation.
First I give a brief review on these models and then focus on the multi-field inflation.  I will show the general condition for large non-Gaussianity for the two-field inflation model with an application to the two-field hybrid inflation scenario.

Beyond delta-N formalism for a single scalar field
Speaker:  Yuichi Takamizu

Abstract: We develop a theory of nonlinear cosmological perturbations on superhorizon scales for a single scalar field with a general kinetic
Term and a general form of the potential. We employ the ADM formalism and the spatial gradient expansion approach, characterised by $O(\epsilon^m)$, where $\epsilon=1/(HL)$ is a small parameter representing the ratio of the Hubble radius to the characteristic length scale $L$ of perturbations.
We obtain the general solution for a full nonlinear version of the curvature perturbation valid up through second-order in $\epsilon
$ ($m=2$). We find the solution satisfies a nonlinear second-order differential equation as an extension of the equation for the linear curvature perturbation on the comoving hypersurface. Then we formulate a general method to match a perturbative solution accurate to $n$-th-order in perturbation inside the horizon to our nonlinear solution accurate to second order ($m=2$) in the gradient expansion on scales slightly greater than the Hubble radius.
The formalism developed in this paper allows us to calculate the
Superhorizon evolution of primordial non-Gaussianity beyond the so-called $\delta N$ formalism or separate universe approach which is equivalent to leading order ($m=0$) in the gradient expansion.
In particular, it can deal with the case when there is a temporary suspension of slow-roll inflation. We will explain our formalism and its applications in my talk.

Non-minimally  coupled  Hybrid  inflation
Speaker:  Seoktae Koh

Abstract: We consider Hybrid inflation in which an inflaton or waterfall field couples to gravity. In order to compare with the present observations we calculate the curvature perturbations  during inflation as well as isocurvature perturbations due to the waterfall field when the tachyonic instability begins.