Niemeier Lattices in the Free Fermionic Heterotic-String Formulation

The spinor-vector duality was discovered in free fermionic constructions of the heterotic-string in four dimensions. It played a key role in the construction of heterotic-string models with an anomaly free extra $Z^\prime$ symmetry that may remain unbroken down to low energy scales. A generic signature of the low scale string derived $Z^\prime$ model is via di-photon excess that may be within reach of the LHC. A fascinating possibility is that the spinor-vector duality symmetry is rooted in the structure of the heterotic-string compactifications to two dimensions. The two dimensional heterotic-string theories are in turn related to the so-called moonshine symmetries that underlie the two dimensional compactifications. In this paper we embark on exploration of this connection by the free fermionic formulation to classify the symmetries of the two dimensional heterotic-string theories. We use two complementary approaches in our classification. The first utilises a construction which is akin to the one used in the spinor-vector duality. Underlying this method is the triality property of $SO(8)$ representations. In the second approach we use the free fermionic tools to classify the twenty four dimensional Niemeier lattices.Comment: 22 pages. Standard LaTex. 1 figure. Title changed in journal. Minor corrections. Published versio

Do bilinguals think differently from monolinguals? Evidence from non-linguistic cognitive categorisation of objects in Japanese-English bilinguals*

Recent advances in the investigation of the relationship between language and cognition have demonstrated that speakers of English categorise objects based on their common shape, while speakers of Yucatec and Japanese categorise objects based on their common material (Lucy & Gaskins 2003; Imai & Mazuka 2003). The current study extends that investigation to the domain of bilingualism. Results from a cognitive categorisation task show that intermediate Japanese L2 English speakers behaved similarly to Japanese monolinguals, while advanced Japanese L2 English speakers behaved similarly to English monolinguals. The implications of these findings for bilingualism and second language acquisition are discussed

The Whorfian time warp:representing duration through the language hourglass

How do humans construct their mental representations of the passage of time? The universalist account claims that abstract concepts like time are universal across humans. In contrast, the linguistic relativity hypothesis holds that speakers of different languages represent duration differently. The precise impact of language on duration representation is, however, unknown. Here, we show that language can have a powerful role in transforming humans’ psychophysical experience of time. Contrary to the universalist account, we found language-specific interference in a duration reproduction task, where stimulus duration conflicted with its physical growth. When reproducing duration, Swedish speakers were misled by stimulus length, and Spanish speakers were misled by stimulus size/quantity. These patterns conform to preferred expressions of duration magnitude in these languages (Swedish: long/short time; Spanish: much/small time). Critically, Spanish-Swedish bilinguals performing the task in both languages showed different interference depending on language context. Such shifting behavior within the same individual reveals hitherto undocumented levels of flexibility in time representation. Finally, contrary to the linguistic relativity hypothesis, language interference was confined to difficult discriminations (i.e., when stimuli varied only subtly in duration and growth), and was eliminated when linguistic cues were removed from the task. These results reveal the malleable nature of human time representation as part of a highly adaptive information processing system

Second language influence on first language motion event encoding and categorization in Spanish-speaking children learning L2 English

Studies show cross-linguistic differences in motion event encoding, such that English speakers preferentially encode manner of motion more than Spanish speakers, who preferentially encode path of motion. Focusing on native Spanish speaking children (aged 5;00-9;00) learning L2 English, we studied path and manner verb preferences during descriptions of motion stimuli, and tested the linguistic relativity hypothesis by investigating categorization preferences in a non-verbal similarity judgement task of motion clip triads. Results revealed L2 influence on L1 motion event encoding, such that bilinguals used more manner verbs and fewer path verbs in their L1, under the influence of English. We found no effects of linguistic structure on non-verbal similarity judgements, and demonstrate for the first time effects of L2 on L1 lexicalization in child L2 learners in the domain of motion events. This pattern of verbal behaviour supports theories of bilingual semantic representation that postulate a merged lexico-semantic system in early bilinguals

Non-Tachyonic Semi-Realistic Non-Supersymmetric Heterotic String Vacua

The heterotic--string models in the free fermionic formulation gave rise to some of the most realistic string models to date, which possess N=1 spacetime supersymmetry. Lack of evidence for supersymmetry at the LHC instigated recent interest in non-supersymmetric heterotic-string vacua. We explore what may be learned in this context from the quasi--realistic free fermionic models. We show that constructions with a low number of families give rise to proliferation of a priori tachyon producing sectors, compared to the non--realistic examples, which typically may contain only one such sector. The reason being that in the realistic cases the internal six dimensional space is fragmented into smaller units. We present one example of a quasi--realistic, non--supersymmetric, non--tachyonic, heterotic--string vacuum and compare the structure of its massless spectrum to the corresponding supersymmetric vacuum. While in some sectors supersymmetry is broken explicitly, i.e. the bosonic and fermionic sectors produce massless and massive states, other sectors, and in particular those leading to the chiral families, continue to exhibit fermi-bose degeneracy. In these sectors the massless spectrum, as compared to the supersymmetric cases, will only differ in some local or global U(1) charges. We discuss the conditions for obtaining $n_b=n_f$ at the massless level in these models. Our example model contains an anomalous U(1) symmetry, which generates a tadpole diagram at one loop-order in string perturbation theory. We speculate that this tadpole diagram may cancel the corresponding diagram generated by the one-loop non-vanishing vacuum energy and that in this respect the supersymmetric and non-supersymmetric vacua should be regarded on equal footing. Finally we discuss vacua that contain two supersymmetry generating sectors.Comment: 31 pages. 10 tables. Minor corrections. Tables are amended. Published versio

The Whorfian Brain:Neuroscientific Approaches to Linguistic Relativity

Modern approaches to the Whorfian linguistic relativity question have reframed it from one of whether language shapes our thinking or not, to one that tries to understand the factors that contribute to the extent and nature of any observable influence of language on perception. The current paper demonstrates that such understanding is significantly enhanced by moving the evidentiary basis toward a more biologically grounded empirical arena. We review recent neuroscientific evidence using a variety of methodological techniques that reveal the functional organisation and temporal distribution of the ubiquitous relationship between language and cognitive processing in the human brain

Motion event categorisation in a nativised variety of South African English

The present study seeks to expand the current focus on acquisition situations in linguistic relativity research by exploring the effects of nativisation (the process by which a L2 is acquired as a L1) on language-specific cognitive behaviour. Categorisation preferences of goal-oriented motion events were investigated in South African speakers who learnt English as a L1 from caregivers who spoke English as a L2 and Afrikaans as a L1. The aim of the study was to establish whether the categorisation patterns found in the nativised English variety: (1) resemble patterns of L2 speakers of English with Afrikaans as a L1, (2) resemble patterns of L1 English speakers of a non-nativised English variety and (3) do not pattern with either of the above, but instead exhibit a distinct behaviour. It was found that simultaneous, functional bilinguals (Afrikaans and nativised English) patterned with L1 Afrikaans speakers, but the extent to which they did so was modulated by their frequency of use of Afrikaans. Functionally monolingual speakers of nativised English, on the other hand, patterned with L1 speakers of British English. This suggests that bilingualism, rather than nativisation, was a reliable predictor of event categorisation preferences

Whorf in the Wild:Naturalistic Evidence from Human Interaction

The past few decades have seen a full resurgence of the question of whether speakers of different languages think differently, also known as the Whorfian question. A characteristic of this neo-Whorfian enterprise is that the knowledge it has generated stems from psycholinguistic laboratory methods. As a consequence, our knowledge about how Whorfian effects play out in naturally occurring behaviour (i.e. ‘in the wild’) is severely limited. This study argues that the time is ripe to redeem this evidentiary bias, and advocates a multidisciplinary approach towards the Whorfian question, in which insights from laboratory settings are combined with naturalistic data in order to yield a rounded picture of the influence of language on thought. To showcase the potential of such an approach, the study uses laboratory-generated knowledge on the influence of grammatical categories on cognition to interpret two examples of naturalistic human interaction and action in the domains of spatial navigation and scientific practice

Cognitive restructuring:Psychophysical measurement of time perception in bilinguals

This paper explores the link between the metaphoric structure TIME IS SPACE and time perception in bilinguals. While there appear to be fundamental commonalities in the way humans perceive and experience time regardless of language background, language-specific spatiotemporal metaphors can give rise to differences between populations, under certain conditions. Little is known, however, about how bilinguals experience time, and the specific factors that may modulate bilingual temporal processing. Here, we address this gap by examining L1 Spanish - L2 Swedish bilinguals in a psychophysical task. Results show that duration estimation of dynamic spatial configurations analogous to L2-specific temporal metaphors is modulated by L2 proficiency. In contrast, duration estimation of spatial configurations analogous to the L1 metaphorical expressions appears to be modulated by the age of L2 acquisition. These findings are discussed in terms of associative learning and cognitive restructuring in the bilingual mind