KEK Cosmophysics Workshop LLTB2009

ĩ-LTB Cosmology

Theory Center, Institute of Particle and Nuclear Studies
High Energy Accelerator Organization (KEK),
Tsukuba, Japan

Tsukuba Campus 4th-Bld 1F Seminar Hall

Oct. 20 - 23, 2009


Recently, in connection with the dark energy problem and the CMB anomaly problems, observational cosmology in the background with large local inhomogeneities such as voids and clusters as a prior is becoming a major research area. Although it is unlikely that the present apparent accelerated expansion is fully accounted for by a local deep void in which we live around the centre, some authors suggest that there may exist a shallow local void responsible for some fraction of the observed acceleration. Further, it is also pointed out that the CMB anomaly is strongly correlated with foreground voids and clusters. In such situations, theoretical implications of the observations of CMB, galaxy clusterings, BAO and weak gravitational lensing on the nature of dark energy and the early universe including inflation may be different from those obtained by the simple ĩ-CDM model.

The main purpose of this workshop is to provide the opportunity for experts in this field to discuss how to push investigations further and start new collaborations on these problems, in particular, the effects of inhomogeneities of the present universe on the observational cosmology and their influence on the dark energy probe and the inflation probe projects. Taking into account the fact that most work on these problems has been based on the analyses of the Lemaitre-Tolman-Bondi spacetime, we mainly focus on the LTB cosmology or its extension with non-vanishing cosmological constant, the ĩ-LTB cosmology, although talks and discussions related to the above problems from wider perspectives are welcome.


Because of the nature of the workshop, group or personal free discussions are going to be given as much time as possible. Further, participants can stay at the Theory Centre after the workshop to collaborate with other participants of the workshop and people of the Theory Centre. The domestic travel and local expenses to attend the workshop and for the additional stay will be provided by the Theory Centre in principle.


Istvan Szapudi (Inst. Aston., U Hawaii)
Valerio Marra (Dept. Phys., U Jyvaskyla)
Timothy Clifton (Dept. Astron., Oxford U)
Shinji Tsujikawa (Dept. Phys., Tokyo U. Sci.)
Michael Blomqvist (Dept. Astron., Stockholm U.)
Naoki Itoh (Dept. Phys., Sofia U.)


Program and talks Participants Campus Map&Guide
Transportation KEK DE2008
Group photo -- --


K. Inoue (Kinki U.), A. Ishibashi (KEK),

M. Kasai ( Hirosaki U. ), H. Kodama (KEK, chair),

K. Nakao (Osaka City U. ), N. Sakai (Yamagata U.),

K. Tomita (Professor Emeritus of Kyoto U.),

J. Yokoyama (RESCEU, U. Tokyo)


Hideo Kodama (Chair), Akihiro Ishibashi, Shinya Tomizawa, Hajime Goto

Cosmophysics Group


Secretary: Ms. Tamao Shishido


Phone: +81-29-864-5393

Fax:  +81-29-864-5755

Address: Theory Division, IPNS, KEK, 1-1 Oho, Tsukuba 305-0501, Japan

Supported by

EHayama Center for Advanced Studies, the Graduate University for Advanced Studies (SOKENDAI).
EMEXT Grant-in-Aid for Scientific Research on Innovative Area 2110
"The Physical Origin of the Universe"Research Group A05 (No.21111006) .
ETheory Center, KEK.