Values-Based Leadership in a Time of Values Confusion

Values-based leadership is slipping, perhaps morphing into an ill-defined expediency without the weight or anchor of moral principles while neglecting common decency, genuine care for others, and a vision of democracy as a moral egalitarianism. Values, without a moral anchor, can easily slip into ethical relativity and narcissistic navel-gazing where a moral view of others hangs hopelessly by the threads of expedient decision making. This we see in the current political and business climate of 2018 as we live and work in an atmosphere of selfishness ignoring self-giving service to others. Will this last, or will we be able to revive our democratic ideals and moral principles and transpose these into our everyday lives, business practices, and political processes

Mirror Mediation

I show that the effective action of string compactifications has a structure that can naturally solve the supersymmetric flavour and CP problems. At leading order in the g_s and \alpha' expansions, the hidden sector factorises. The moduli space splits into two mirror parts that depend on Kahler and complex structure moduli. Holomorphy implies the flavour structure of the Yukawa couplings arises in only one part. In type IIA string theory flavour arises through the Kahler moduli sector and in type IIB flavour arises through the complex structure moduli sector. This factorisation gives a simple solution to the supersymmetric flavour and CP problems: flavour physics is generated in one sector while supersymmetry is broken in the mirror sector. This mechanism does not require the presence of gauge, gaugino or anomaly mediation and is explicitly realised by phenomenological models of IIB flux compactifications.Comment: 33 pages, 1 figure; v2: typos, references, minor correction

The de Sitter swampland conjecture and supersymmetric AdS vacua

It has recently been conjectured that string theory does not admit de Sitter critical points. This note points out that in several cases, including KKLT or racetrack models, this statement is equivalent to the absence of supersymmetric Minkowski or AdS solutions. This equivalence arises from establishing the positivity of the potential in a large-radius limit, requiring a turnover of the potential before reaching an AdS vacuum. For example, this conjecture is incompatible with the simplest 1-modulus KKLT AdS supersymmetric solution.Comment: Prepared for submission to Int. Journ. Mod. Phys. A; v2. added references and more discussio

The QCD Axion and Moduli Stabilisation

We investigate the conditions for a QCD axion to coexist with stabilised moduli in string compactifications. We show how the simplest approaches to moduli stabilisation give unacceptably large masses to the axions. We observe that solving the F-term equations is insufficient for realistic moduli stabilisation and give a no-go theorem on supersymmetric moduli stabilisation with unfixed axions applicable to all string compactifications and relevant to much current work. We demonstrate how nonsupersymmetric moduli stabilisation with unfixed axions can be realised. We finally outline how to stabilise the moduli such that f_a is within the allowed window 10^9 GeV < f_a < 10^{12} GeV, with f_a ~ \sqrt{M_{SUSY} M_P}.Comment: 36 pages; v2: extended discussion of cosmological bound on f_a, references added, version accepted by journal; v3. factor of 2 correcte