Iranian Mathematical Society
Journal of the Iranian Mathematical Society
2717-1612
1
1
2020
01
01
Shing-Tung Yau's work on the notion of mass in general relativity
1
3
EN
M.-T.
Wang
Department of Mathematics,
Columbia University, 2990 Broadway, New York, NY 10027.
mtwang@math.columbia.edu
10.30504/jims.2020.105265
The notion of mass or energy has been one of the most challenging problems in general relativity since Einstein's time. As is well known from the equivalence principle, there is no well-defined concept of energy density for gravitation. On the other hand, when there is asymptotic symmetry, concepts of total energy and momentum can be defined. This is the ADM energy-momentum and the Bondi energy-momentum when the system is viewed from spatial infinity and null infinity, respectively. These concepts are fundamental in general relativity but there are limitations to such definitions if the physical system is not isolated and cannot quite be viewed from infinity where asymptotic symmetry exists.<br /><br />The positive energy conjecture states that the total energy of a nontrivial isolated physical system must be positive. This conjecture lies in the foundation of general relativity upon which stability of the system rests.This long standing conjecture had attracted many physicists and mathematician,<br />but only very special cases were verified up until the seventies.
Mass,General Relativity,Positive energy conjecture
https://jims.ims.ir/article_105265.html
https://jims.ims.ir/article_105265_9b45902aae90b22ffdb5c61d4bcb0aa2.pdf
Iranian Mathematical Society
Journal of the Iranian Mathematical Society
2717-1612
1
1
2020
01
01
Moduli of $J$-holomorphic curves with Lagrangian boundary conditions and open Gromov-Witten invariants for an $S^1$-equivariant pair
5
95
EN
C.C. Melissa
Liu
Department of Mathematics, Columbia University,
2990 Broadway, New York, NY 10027.
ccliu@math.columbia.edu
10.30504/jims.2020.104185
Let $(X,\omega)$ be a symplectic manifold, $J$ be an $\omega$-tame almost complex structure, and $L$ be a Lagrangian submanifold. The stable compactification of the moduli space of parametrized $J$-holomorphic curves in $X$ with boundary in $L$ (with prescribed topological data) is compact and Hausdorff in Gromov's $C^\infty$-topology. We construct a Kuranishi structure with corners in the sense of Fukaya and Ono. This Kuranishi structure is orientable if $L$ is spin. In the special case where the expected dimension of the moduli space is zero, and there is an $S^1$-action on the pair $(X,L)$ which preserves $J$ and has no fixed points on $L$, we define the Euler number for this $S^1$-equivariant pair and the prescribed topological data. We conjecture that this rational number is the one computed by localization techniques using the given $S^1$-action.
Moduli of $J$-Holomorphic Curves,Lagrangian boundary conditions,Open Gromov-Witten Invariants
https://jims.ims.ir/article_104185.html
https://jims.ims.ir/article_104185_c86f22dd64c9c7ae78d34f83e9d829f4.pdf
Iranian Mathematical Society
Journal of the Iranian Mathematical Society
2717-1612
1
1
2020
01
01
Canonical sections of Hodge bundles on moduli spaces
97
115
EN
K.
Liu
Department of Mathematics, University of California at Los Angeles, Los Angeles, CA 90095-1555, USA
liu@math.ucla.edu
Y.
Shen
Department of Mathematics, Nanjing University, Nanjing 210093, P.R.China
syliuguang2007@163.com
10.30504/jims.2020.104186
We review recent works in [K. Liu, S. Rao, and X. Yang, Quasi-isometry and deformations of Calabi Yau manifolds, Inventiones mathematicae, 199(2) (2015), 423–453] and [K. Liu and Y. Shen, Moduli spaces as ball quotients I, local theory, preprint] on geometry of sections of Hodge bundles and their applications to moduli spaces.
CANONICAL SECTIONS,HODGE BUNDLES,MODULI SPACES
https://jims.ims.ir/article_104186.html
https://jims.ims.ir/article_104186_5aeacde0efd83615df987f55d36727c2.pdf
Iranian Mathematical Society
Journal of the Iranian Mathematical Society
2717-1612
1
1
2020
01
01
Weil-Petersson metrics on deformation spaces
117
128
EN
H.-D.
Cao
Department of Mathematics, Lehigh University, Bethlehem, PA 18015, USA.
huc2@lehigh.edu
X.
Sun
Department of Mathematics, Lehigh University, Bethlehem, PA 18015, USA.
xis205@lehigh.edu
S.-T.
Yau
Department of Mathematics, Harvard University, Cambridge, MA 02138, USA.
yau@math.harvard.edu
Y.
Zhang
Yau mathematical Sciences Center, Tsinghua University, Beijing, 100804, China.
zhangyingying@math.tsinghua.edu.cn
10.30504/jims.2020.104184
In this paper we survey various aspects of the classical wpm and its generalizations, in particular on the moduli space of ke manifolds. Being a natural $L^2$ metric on the parameter space of a family of complex manifolds (or holomorphic vector bundles) which admit some canonical metrics, the wpm is well defined when the automorphism group of each fiber is discrete and the curvature of the wpm can be computed via certain integrals over each fiber. We shall discuss the Fano case when these fibers may have continuous automorphism groups. We also discuss the relation between the wpm on Teichm"uller spaces of K"ahler-Einstein manifolds of general type and energy of harmonic maps. <br /><br />In this paper we survey various aspects of the classical wpm and its generalizations, in particular on the moduli space of ke manifolds. Being a natural $L^2$ metric on the parameter space of a family of complex manifolds (or holomorphic vector bundles) which admit some canonical metrics, the wpm is well defined when the automorphism group of each fiber is discrete and the curvature of the wpm can be computed via certain integrals over each fiber. We shall discuss the Fano case when these fibers may have continuous automorphism groups. We also discuss the relation between the wpm on Teichm"uller spaces of K"ahler-Einstein manifolds of general type and energy of harmonic maps.
Weil-Petersson metrics,Deformation Spaces,moduli space
https://jims.ims.ir/article_104184.html
https://jims.ims.ir/article_104184_b5c880cdd6543fe6c6b09d421a48be6a.pdf