University of Melbourne Events Calendar

Although close to Athens, Kythnos remains one of the lesser-known islands of the Cyclades. Its capital, today called Vryokastro, has a rich ancient history from the 12th century BC to the 7th century AD. Land and underwater fieldwork have brought to light four sanctuaries, each dedicated to different deities. One of these was unplundered, a unique finding that greatly advances our knowledge about the use of ancient Greek temples from the Archaic period to the Roman era.

This public lecture presents this exceptional discovery, as well as Vyrokastro’s other temples, its settlement on the acropolis, the Hellenistic ‘prytaneion’, a proto-Byzantine basilica church, and the city’s harbour installations, to celebrate what has been called ‘the best Greek island you have never heard of’.

This public lecture is co-sponsored by the Classical Association of Victoria (CAV), which since 1912 has operated for the propagation and well-being of Classics and Ancient World Studies in the state of Victoria; and by the Australian Archaeological Institute at Athens (AAIA), which is the national centre for advanced research by Australian scholars on the Hellenic world from the distant past to the modern day. Both the CAV and the University of Melbourne are Institutional Members of the AAIA.

Co-hosted by: MIQT and OPTIMA

Time: 16:00 – 17:00 Seminar, followed by light refreshments until 17:30

Abstract:

Over the last two decades, the travelling salesperson problem (TSP) has been used as a benchmark problem to explore the advantage of quantum computers over conventional computers. Its advantages include being easy to understand, highlighting the challenges of searching through an exponentially growing number of possible solutions, with direct applications to large-scale transportation and logistics problems in industry.

However, we argue that the TSP is not a problem well-suited to current QUBO-based quantum optimisation methods (like quantum annealing (QA) and QAOA). At what point is a call made that quantum advantage is not likely, and efforts should be focused on other problems?

This talk reviews 20 years of efforts to conclude current quantum methods are unlikely to ever be competitive with the classical state of the art for TSP and many other constrained optimisation problems. We offer mathematical arguments for why QUBO-based methods are not well suited for tackling the challenges of the TSP landscape, drawing parallels with similar observations made almost four decades ago for QUBO-based neural networks.

We discuss the numerous challenges that must be overcome for current quantum methods to handle constrained optimisation. Finally, we discuss more promising directions for quantum optimisation using non-QUBO-based hybrid approaches, where quantum search could accelerate components of conventional algorithms.

This talk is based on the following recently published paper in Quantum Science and Technology:

https://iopscience.iop.org/article/10.1088/2058-9565/add61d