## Vee Liem Saw

Studying for Doctor of Philosophy

Area of study:**Further investigations on the general method of constructing spacetime by generating manifolds of revolution around a given curve**

Supervisor: Jörg Frauendiener—

Email: sawve240@student.otago.ac.nz

### Thesis

Title: Bondi mass-loss with cosmological constant, due to energy carried by gravitational radiation

Supervisors: Jörg Frauendiener, Jörg Hennig

Previous Degree: BSc with first class honours (Nanyang Technological University, Singapore)

The theoretical basis for the energy carried away by gravitational waves that an isolated gravitating system emits was first formulated by Hermann Bondi during the 1960s. Recent findings from looking at distant supernovae revealed that the rate of expansion of our universe is accelerating (Nobel Prize in Physics, 2011), which may be well-explained by sticking in a positive cosmological constant into the Einstein field equations for general relativity. By solving the Newman-Penrose equations (which are equivalent to the Einstein field equations), we generalise this notion of Bondi-energy and thereby provide a firm theoretical description of how an isolated gravitating system loses energy as it radiates gravitational waves, in a universe that expands at an accelerated rate 1. This is in line with the observational front of LIGO's announcement in February 2016 that gravitational waves from the merger of a binary black hole system have been detected.

### Research papers (peer-reviewed)

- V.-L. Saw, “Asymptotically simple spacetimes and mass loss due to gravitational waves”, International Journal of Modern Physics D, 26, 1730027 (2017). (This is a review article.) http://www.worldscientific.com/doi/abs/10.1142/S0218271817300270
- V.-L. Saw, “Mass loss due to gravitational waves with positive Lambda”, Modern Physics Letters A, 32, 1730020 (2017). (This is a brief review.) http://www.worldscientific.com/doi/abs/10.1142/S0217732317300208
- V.-L. Saw, “Behaviour of asymptotically electro-Lambda spacetimes”, Physical Review D 95, 084038 (2017). https://journals.aps.org/prd/abstract/10.1103/PhysRevD.95.084038
- V.-L. Saw, “Mass-loss of an isolated gravitating system due to energy carried away by gravitational waves with a cosmological constant”, Physical Review D 94, 104004 (2016). https://journals.aps.org/prd/abstract/10.1103/PhysRevD.94.104004
- V.-L. Saw, “Constructing vacuum spacetimes by generating manifolds of revolution around a curve”, Classical and Quantum Gravity, 33, 065006 (2016). http://iopscience.iop.org/article/10.1088/0264-9381/33/6/065006
- V.-L. Saw and L.Y. Chew, “Helicalised fractals”, Chaos, Solitons and Fractals, 75, 191 (2015). http://www.sciencedirect.com/science/article/pii/S0960077915000442
- V.-L. Saw and L.Y. Chew, “Curved traversable wormholes in (3+1)-dimensional spacetime”, General Relativity and Gravitation, 46, 1655 (2014). http://link.springer.com/article/10.1007%2Fs10714-013-1655-1
- V.-L. Saw and L.Y. Chew, “A general method for constructing curved traversable wormholes in (2+1)-dimensional spacetime”, General Relativity and Gravitation, 44, 2989 (2012). http://link.springer.com/article/10.1007%2Fs10714-012-1435-3

### Conference proceeding (peer-reviewed)

- V.-L. Saw, “Mass loss due to gravitational waves with positive Lambda”, talk based on Refs. 3 and 4 given at the Conference on Cosmology, Gravitational Waves and Particles, held at the Institute of Advanced Studies, Nanyang Technological University, Singapore, 6th to 10th of February 2017. --- Published as a brief review in Modern Physics Letters A (Ref. 2, above).

### Preprints

- V.-L. Saw, “Peeling property with a cosmological constant”. https://arxiv.org/abs/1705.00435
- V.-L. Saw, “A rotating universe outside a Schwarzschild black hole where spacetime itself non-uniformly rotates”. http://arxiv.org/abs/1403.0337.
- F.C.S. Thun, V.-L. Saw, and K.S. Chan, “A theory of static friction between homogeneous surfaces based on compressible elastic smooth microscopic inclines”. http://arxiv.org/abs/1407.3103.